Members indicated that the quick turnaround time for the majority leader election has played to McCarthy's strengths.
"You're running almost purely on reputation and existing relationships, so having been whip for some time, that's why it's an easy and logical choice to continue with someone you're already happy with," Rep. Jason Chaffetz of Utah said.
Rooney said he supported McCarthy because he's accessible and "one of the few adults in the room."
As the House whip, it's McCarthy's responsibility to mobilize and count the party vote on important legislation. During his tenure, the House leadership has at times pulled bills from consideration when it turned out they did not have as much support as anticipated. "Some of that is the growing pains of a majority," Camp explained.
McCarthy, who faced no opposition in his 2014 primary race, has had one of the more moderate voting records among House Republicans in recent years. Club for Growth, a conservative advocacy group, ranked McCarthy in the bottom quarter of House Republicans for 2013.
FreedomWorks, an advocacy group affiliated with the tea party movement, called on its members Friday to pressure their representatives to vote for Labrador.
"Americans deserve a choice in leadership, and thanks to Raul Labrador, Republicans don't have to settle for the next guy in line," said the group's president, Matt Kibbe.
As a teenager, McCarthy used a $5,000 win in the lottery to jump-start his own business, Kevin O's Deli. He sold the business and used the profits to attend college, where he accepted an internship with Thomas and went on to become his district director.
McCarthy ranks in the lowest fifth among House members in terms of wealth, according to his financial disclosure statements and an analysis by the Center for Responsive Politics. His 2012 disclosure showed his net worth between $78,000 and $296,000, with his $174,000 congressional salary supplemented from dividends from a variety of mutual and money market funds.
He would make more than $193,000 if he wins the majority leader post.
Associated Press writer Erica Werner contributed to this report.
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