WATERLOO, Iowa — The last time Ted Cruz visited this state — just under two weeks ago — he resisted any and all opportunities to criticize Donald Trump, part of a months-long mission to keep the peace with the Republican presidential frontrunner.

All that was a distant memory Saturday as Cruz, the U.S. senator from Texas, launched his final tour of Iowa issuing warnings about the billionaire both implicit and explicit, a reversal that illustrates just how much the race has tightened here with nine days until the first-in-the-country caucuses. Making his way through the northeast part of the state, Cruz volunteered contrast after contrast with Trump as he sought to close the deal with Iowans, cautioning them against getting "burned again" by a politician whose record does not match his rhetoric. 

The warning has emerged as Cruz's closing argument in the early voting states, where the Iowa contest increasingly looks like the senator's best shot at halting Trump in the near term. The urgency was palpable Saturday as Cruz unveiled the endorsement of conservative radio host Glenn Beck, who pummeled Trump as an unprincipled narcissist and warned he would be a "snowball to hell" if he won the caucuses. 

In a pair of rallies with Beck in Ankeny and Waterloo, Cruz recounted his role in seven recent battles over conservative priorities, strongly suggesting Trump was missing in action for most of them. Throughout his remarks, Cruz largely avoided direct references to Trump, but in Ankeny, he made an exception, naming the billionaire as he sought to undermine him on his calling card: illegal immigration. Cruz made the case that Trump is not as tough on the issue as he claims to be, citing Trump's support for immigration reform efforts in 2013 and for allowing deported people to ultimately re-enter the United States.

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"Now he's entitled to advocate for that — a lot of establishment Republicans have advocated for that — but he doesn't get to pretend he's not for amnesty when he's making 12 million people here illegally into 12 million U.S. citizens," Cruz said, earning scattered but not overwhelming applause for what ended up being his sharpest criticism of Trump of the day. 

Trump was also a topic of conversation in between the rallies, when Cruz made two stops in small towns surrounding Waterloo. Inside a pizza joint in the small city of Dike, Cruz echoed Beck's egomaniac charge against Trump and added, "Any person who thinks they are the salvation" for the country does not understand it. Inside a community center in New Hartford, Cruz suggested Trump's coziness with Democrats, both ideologically and politically, would make for a weak contrast in the general election. 

"If we nominate a candidate who has the same substantive positions as Hillary Clinton, we will lose," Cruz said, alluding to Trump's support for partial-birth abortion and donations to Democratic causes. "We nominate a candidate who has been part of the cronyism in Washington, part of writing checks to the Clinton Foundation, we give away our ability to win."

Cruz supporters, long accustomed to the senator's anti-aggression pact with Trump, appeared pleased with his increasingly aggressive stance toward the billionaire. Brett Davis, a truck driver from Independence, said Cruz's arguments against Trump could propel the senator to a first-place finish in the caucuses "if people actually listen and think about it."

 "We don't have any proof with Trump that he can" fight for conservative values, said Davis, who came to see Cruz in Waterloo. "Cruz has been out there fighting for us for years. It's not going to change."

The closeness of the caucuses loomed over the day's events, especially at both rallies, where Beck spoke alarmingly of Trump potentially cruising to the nomination if he wins in Iowa. In Waterloo, Beck said the media and Republican establishment are eagar to "steamroll him into the general election," where they will "pick his bones apart and destroy him." After the rally in Ankeny, Beck told reporters Trump "might be" unstoppable if he wins the caucuses. 

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"My gut feeling is that people are angry and the people on the right, they just want to win and they're tired of losing, and that's a very dangerous place to be," Beck said. "If you have the image of win, win, win, I think it's going to happen very quickly."

If Trump ends up as the nominee, Beck added, he would not support him. 

The opening day of Cruz's final tour of Iowa unfolded while Trump also traveled the state, continuing to raise questions about Cruz's eligibility to be president as well as undisclosed loans from his 2012 Senate race. In Sioux Center, Trump touted the devotion of his supporters, saying he "could stand in the middle of 5th Avenue and shoot somebody and I wouldn't lose voters."

Beck took umbrage with that pronouncement while speaking with reporters after the rally in Ankeny, saying it shows how Trump harbors "hubris beyond imagination." Asked for his take on Trump's remark, Cruz offered a promise that illustrated just how topsy-turvy the race has become.

"I will say I have no intention of shooting anybody in this campaign," the senator deadpanned.