Almost eight years ago, before he became a state senator, Dan Patrick was known around the Texas Capitol as the Houston talk radio host who had once shouted down a powerful committee chairman in the middle of a legislative hearing.

Now Patrick, a Republican, is in prime position to control its most powerful post. He is the front-runner in a Republican primary runoff for lieutenant governor in May after a primary in which he finished 13 points ahead of the incumbent, David Dewhurst, who received just 28 percent of the vote. The runoff winner will be a strong favorite in the general election against state Sen. Leticia Van de Putte, D-San Antonio.

If Patrick succeeds Dewhurst, who has held the office for 11 years, it would begin a new era in a state Senate, where Patrick’s flair for showmanship and populist appeal once branded him as an outsider.

In a primary night speech, Patrick credited his success to grassroots support, saying, “The people’s voice took the first step of going to the lieutenant governor’s office in the state of Texas.”

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But his momentum has also been built on lessons learned navigating the old-school politics of Harris County, where he has aggressively courted a small number of influential conservatives.

Among Patrick’s foremost backers is Steven Hotze, a Houston doctor and Republican donor, who like Patrick is a longtime client of Allen Blakemore, a political consultant. Hotze’s political action committee, Conservative Republicans of Texas, distributed an estimated 1.2 million mailers promoting Patrick among a slate of candidates during the 2014 primary in all but eight counties in the state.

According to campaign finance filings, Patrick spent $50,000 each on advertising in the state’s two other largest Harris County-based slate publishers — the Link Letter and the Texas Conservative Review, which both mail their lists to primary voters statewide.

Such methods have drawn criticism for what is perceived as a “pay to play” approach, in which candidates donate money or pay for advertising in exchange for an endorsement.

Joe Slovacek, a Houston lawyer who is the treasurer of the Houston Realty Business Coalition, said he did not fault candidates for using slate cards because they often presented a cost-effective way to get their message to voters. But he said the organizations that put them out often did not pass the “smell test.”

His group, which has not endorsed anyone in the lieutenant governor’s race, has attempted to combat the influence of slate cards in Harris County by putting out its own mailer that is not paid for by political contributions.

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“There is one person making decisions. They don’t have a board; they don’t vote,” he said of the cards. “They sell ads, sometimes to the highest bidder.”

Gary Polland, who has published Texas Conservative Review for 13 years, said he allowed candidates who are not endorsed by the group to pull their ads and get their money back. He said that he had chosen to endorse Patrick after lengthy meetings with both the Houston senator and his opponent.

Polland said he was impressed by Patrick’s willingness to talk about concrete issues facing the state.

“I like David and consider him to be a friend. But I never could determine what he wanted to accomplish in another four years that he hadn’t had a chance to do in the previous time he had served,” Polland said. “And so at the end of the day, I decided that Dan was the one who was more interested in public policy and who had the opportunity to take care of things.”

In a statement, Dewhurst’s campaign said that the incumbent was “focused on his vision for the future of Texas” and was “personally reminding voters of everything this state has accomplished under his leadership.”

Blakemore said he believed the endorsements played a “key role” in delivering Patrick’s margin of victory on primary night. While Patrick appeared early on to be Dewhurst’s toughest challenger in the four-man Republican primary race, many political observers believed he would struggle to build name identification outside of Harris County and with the logistics of running as a statewide candidate for the first time.

But even a steady stream of attacks from his opponents — including claims of dishonesty from other candidates in the race, and reports about undocumented immigrants who had worked in a chain of sports restaurants he owned in the 1980s — failed to curtail Patrick’s strong primary showing.

An early sign of Patrick’s talent for leveraging popular support came in the aftermath of his 2003 standoff in the committee hearing.

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With supporters in tow, Patrick had come to Austin to testify in favor of a bill that would lower the state’s property tax appraisal cap. About two and a half hours in, Patrick — upset because he said lobbyists who opposed the measure had been allowed to speak before him — shouted from the crowd that as a Republican, the committee’s chairman, state Rep. Fred Hill, of Richardson, “should be ashamed.”

Hill, who declined to comment for this article, said at the time that he had allowed seniors and witnesses with disabilities to speak first so they could avoid the several hours of waiting it would take to get to their testimony. Patrick, who walked out after his outburst but later returned to the hearing and testified, maintained that he acted to ensure citizens would have their voices heard.

A decade later, Patrick defended himself in a similar manner when a feud erupted between him and a fellow state senator, Tommy Williams, R-The Woodlands.

Williams, who led the upper chamber’s finance committee until he resigned last year, accused Patrick of taking an unexpected vote against the 2013 state budget to help his campaign for lieutenant governor.

When Patrick later said his vote was because of a lack of funding in the budget for some public education programs, Williams, who also declined to comment for this article, wrote a column published in The Texas Tribune challenging his comments.

Patrick promptly issued a statement defending his choice as what was right for the people of Texas.

“His attack on me is a classic example of a politician who has forgotten that we represent the people first and foremost,” Patrick said in a statement. “I don’t have to explain my vote to Tommy Williams. I have to explain my vote to the people, and I’m happy to do that.”