WAVERLY, Iowa — After logging hundreds of miles on Iowa's snow-dusted roads last week, Ted Cruz ended his massive bus tour of the state Saturday night on a lighter note with the media he so often criticizes. 

"I'm tempted to announce that we're going to launch another six days and 28 counties starting tomorrow, but I'm afraid y'all would take your cameras and beat me over the head with 'em," the Texas senator told reporters before his last stop.

Despite the joke — met by nervous laughter from a weary press corps — Cruz's big swing through the state was about making a serious case. A case that his rise to the front of the GOP pack in Iowa is not a flash in the pan. That he can weather the scrutiny that comes with taking the lead in the first-in-the-country caucus state. And that he can beat his rivals on the ground even if he's already overtaken them in the polls.

Here are five takeaways from Cruz's exhaustive visit to the Hawkeye State: 

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1. Cruz is working Iowa hard — and he really wants you to know it.

Cruz's six-day, 28-county bus tour marked his most ambitious swing through an early voting state yet — and perhaps the most aggressive itinerary the Hawkeye State has seen this cycle from a White House hopeful. While Cruz was ducking in and out of packed convenience stores and coffee shops in the far reaches of Iowa, questions were again cropping up about how committed his two closest competitors are to the attention-hungry caucus state. 

The contrast was not lost on Cruz, who throughout the trip spoke effusively of the "Iowa way" of campaigning: building support county by county, one voter interaction at a time. He also revived a thinly veiled shot at U.S. Sen. Marco Rubio of Florida, remarking that candidates cannot win the caucuses — or the next contest in New Hampshire, for that matter — from the safe confines of television studios in New York and Washington, D.C.

Cruz most sharply hinted at the contrast Friday night in Decorah, where a member of the audience said he knows a lot of people supporting either Cruz or billionaire Donald Trump. 

"I believe the only way to compete and win in the state of Iowa is to come and spend the time asking the voters for their support, looking them in the eye, having the humility to submit yourself to the men and women of this state and to ask and answer the hard questions," Cruz replied. "And if a candidate is not doing that, that ought to be an indication." 

It was not the first time Trump's fly-in, fly-out approach to Iowa came up on Cruz's tour. Asked a day earlier in Mason City if he believes Trump has "worked hard enough in Iowa," Cruz characteristically told reporters he is focused on his own campaign — but not before playfully noting he is "confident that I'm never going to have a plane with my name painted on it."

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2. The ethanol lobby broke through.

Heading into Cruz's bus tour, the pro-ethanol group America's Renewable Future had promised to hold Cruz's feet to the fire. The group, helmed by the son of Iowa Gov. Terry Branstad, had been hitting Cruz for weeks over his opposition to the Renewable Fuel Standard, which sets the minimum amount of ethanol to be blended into the U.S. gasoline supply. Cruz and his aides had been largely dismissing the group's offensive as a misinformation campaign. 

By the end of the Iowa blitz, it was clear Cruz was taking the issue more seriously, even if he still viewed the group's charges as bogus. He arrived in the state with a new, extensive answer ready for anyone who pressed him on ethanol. He wrote an op-ed in The Des Moines Register that pushed back on the group's offensive but also went into a new level of detail. And during the second half of the trip, he was joined on the campaign trail by Dave Vander Griend, the CEO of an ethanol plant design firm. 

Still, audience members asked Cruz roughly a dozen times about his ethanol position, questions that ranged from curious to confrontational. At a few events where Cruz did not receive a question from the audience about ethanol, he brought it up on his own. 

As Cruz's tour wound down Saturday evening, the group said it had accomplished the previously un-accomplishable: It forced Cruz to elaborate on his ethanol views. The group also claimed victory for getting Cruz to say he supports phasing out the fuel standard by 2022, a position Cruz's campaign insisted is not new. 

"Throughout the last year, he has not wanted to say the word, he has not wanted to talk about ... any of that," said Eric Branstad, the group's state director. "It has been our mission this week to get him to talk about it." 

America's Renewable Future had a presence at every stop on Cruz's tour, most notably in the form of an RV parked outside, but Branstad denied that the group was planting the questions in Cruz's crowds. "This was completely organic," Branstad said. 

Ethanol remained omnipresent on the campaign trail through even the final minutes of Cruz's tour, when he paused on his way out of a nearly empty auditorium in Waverly to take one last question on the topic. A roughly 10-minute exchange ensued between Cruz and Jerry Calease, a farmer who pled with Cruz for more information on his ethanol position as aides motioned it was time to go. After the interaction, Calease told reporters he still felt "very divided" about whether to support Cruz. 

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3. Other lines of attack aren't catching on. 

Cruz headed into Iowa on Monday facing a new level of scrutiny befitting his top-tier status in the state. Since the holidays, the list of presidential candidates throwing darts his way had grown to include just about every member of the GOP field, a point Cruz gladly made throughout the trip.

Yet beyond the offensive by the ethanol lobby, there were not many signs that the flurry of attacks was on the minds of Iowans. In nearly two dozen Q-and-As with audiences, Cruz was asked only a handful of times about his rivals' latest charges: once about Trump questioning his eligibility to be president based on Cruz's Canadian birth and one or two times about Cruz's vote for the USA Freedom Act, a bill Rubio has said weakened U.S. intelligence capabilities.

“You know, as we travel the state of Iowa, none of these silly attacks that the other candidates are pushing are being raised by real, live voters,” Cruz told reporters Wednesday in Webster City, moments after shrugging off questions about Trump’s citizenship gambit.

After Cruz's final town hall of the trip on Saturday night, Darrell and Joann Blasberg, a couple from Waverly, said they were mostly unfamiliar with the most recent knocks against Cruz. Joann Blasberg gestured as if she were tearing paper when asked about the mailers that fill Iowans' mailboxes this time of year, while Darrell Blasberg voiced agreement with Cruz's declaration — repeated at every stop on the tour — that the "silly season" is upon Iowans. 

"Don't waste the TV's time and your money and my intelligence cutting somebody down. Tell me what you're going to do. I don't care what the other guy says about you," said Darrell Blasberg, who's active in veterans issues. "That's where you got to vote, not on how good you can butcher somebody else."

4. Iowa has made Cruz a retail politician — sort of.

No one would ever accuse Cruz of being the most likable guy running for president, though a poll during his trip found he had the highest net favorability rating of any candidate in the GOP field. Cruz himself conceded as much during a memorable debate moment last year, saying he may not be the candidate with whom voters would like to grab a beer. 

But after dozens upon dozens of events last year in Iowa, and with this most recent trip, it has become clear the state has made a more adept retail politician out of the Texas senator.

Not much has changed in terms of the format of his Iowa trips: For months, he's been hitting mom-and-pop stores in dot-on-the-map towns, staying late to answer questions friendly and unfriendly, all face-to-face with Iowans. However, Cruz seemed more interested than ever on the last swing in making a personal connection. Asked more than once about disease prevention, he mentioned his mother's battle with breast cancer. He sought to connect with younger questioners by noting he paid off his student loans only several years ago. 

Part of Cruz's conversion could be attributed to his commitment to visit all 99 counties in Iowa, a tradition known as the Full Grassley — named after the state's senior senator — that forces candidates into intimate settings across the state. As he waited for Cruz inside a packed convenience store Friday afternoon in Manly (pop. 1,313), Cruz supporter David Starr said the senator's tiny-town politicking could go a long way toward sealing the deal with Iowans. 

"You go to some of these appearances and you'll hear people be like, 'This is the only presidential candidate that's ever showed up here in all of the years,'" said Starr, a senior at Iowa State University. "I think those people will actually go out and vote for him."

Still, Cruz can have awkward moments on the campaign trail, some more of his own making than others. The latest self-inflicted head-scratcher came Friday afternoon in Charles City, where he drew a bizarre parallel between spanking his five-year-old daughter and holding Hillary Clinton, the former secretary of state, accountable for the 2012 Benghazi terrorist attacks.

Another uncomfortable scene unfolded Wednesday night in Storm Lake, where Cruz was confronted by a woman who said she was a recipient of President Barack Obama's Deferred Action for Childhood Arrivals program, which seeks to prevent the deportation of millions of people living in the country illegally. Audibly nervous, she expressed concern about the potential end of the program under a Cruz presidency. 

"I would note that if you're a DACA recipient, you were brought here illegally, and violating the laws have consequences," Cruz flatly responded, providing instant fodder for his Democratic critics. 

5. Cruz may be the frontrunner, but Trump looms.

All in all, Cruz's bus-bound journey through Iowa affirmed his status as a frontrunner with the will, message and resources to compete there — and hard. As Cruz traipsed across the state, Fox News released the first major post-Christmas poll of the GOP field in the Hawkeye State, finding Cruz maintaining a single-digit lead over Trump.

The billionaire is a wild card to many candidates, but acutely for Cruz, who has vigorously refused to criticize Trump in a perceived effort to ultimately win over his supporters. That's even as Trump has turned on Cruz, as recently as Sunday further chipping away at their anti-aggression pact by stirring the pot regarding Cruz's citizenship and diving into the ethanol-related pile-on. 

The feeling, even among some Cruz supporters, is that Cruz's lead in Iowa is tenuous, especially considering the unpredictable nature of the bombastic rival nipping at his heels. 

"Right now, the only real potential challenge to him is Donald Trump," said Christopher Larimer, a political science professor at the University of Northern Iowa. The extent of that challenge, Larimer added, is "hard to gauge because the Trump factor is so unknown. It’s hard to know how real his support is. Is it real support or is it just fascination?"

Cruz allies in the Hawkeye State are just as curious as they launch their final push to identify and turn out caucus-goers for Cruz. Whether Trump can motivate the thousands of people showing up at his rallies to actually vote for him has long been a subject of fascination.

"That's the biggest question, and it has been the biggest question since basically July," said Jeff King, the son of U.S. Rep. Steve King of Iowa and an operative for a pro-Cruz super PAC. "I think it's one of things you won't know it until it happens."

As the sun set Saturday evening in northeast Iowa, Cruz ended the bus tour a lot like the way it began more than 100 miles away: patiently fielding questions from reporters about Trump's broadsides, emphatically declining to engage. The controversy du jour: Trump's strong suggestion at a rally earlier Sunday in Iowa that Cruz is not a natural-born citizen, an escalation in the billionaire's rhetoric on the topic.

"I recognize that there are candidates in the field that don't want to talk about [the] issues, and they want to instead encourage the good people of the media to go down rabbit trails and engage in silly sideshows," Cruz told reporters before he took the stage for his last town hall of the trip in Waverly. "I don't think the American people are interested."