Mitt Romney is snatching up endorsements from high-ranking lawmakers on both sides of the Capitol, but sources say there is not a leadership-led effort to help the former Massachusetts governor. 

Republican Conference Vice Chairwoman Cathy McMorris Rodgers (Wash.) on Wednesday became the highest-ranking House member to back Romney’s presidential bid. Last month, Sen. John Thune (R-S.D.), chairman of the Republican Policy Committee, formally endorsed Romney. And earlier this fall, House GOP leadership Chairman Greg Walden (R-Ore.) backed him. 

In recent weeks, rival Newt Gingrich has soared in the polls, sparking worry among many congressional Republicans that the former House Speaker will win the nomination. 

{mosads}Romney has wide support among congressional GOP legislators, attracting 55 endorsements thus far. Gingrich, meanwhile, only has seven, according to The Hill’s tally.

Clearly, there is angst over the prospects of a Gingrich nomination. Over the last few weeks, Romney has picked up about a dozen congressional endorsements while the Georgia Republican snared just one, from freshman Rep. Andy Harris (R-Md.). 

Sources told The Hill earlier this week that Sen. John McCain (R-Ariz.) is strongly considering endorsing Romney. 

Speaker John Boehner (R-Ohio) and Senate Minority Leader Mitch McConnell (R-Ky.) have vowed to stay neutral, though many Capitol Hill observers are reading between the lines.

For example, Rep. Mike Simpson (R-Idaho), who is close to Boehner, has backed Romney, and a handful of Boehner’s committee chairmen have done likewise. 

Nine of McConnell’s GOP colleagues in the upper chamber are backing Romney; none have gotten behind Gingrich. 

Boehner denied on Wednesday that he was part of a group of rising Republican stars in 1997 who secretly tried to oust then-Speaker Gingrich.

“That was someone’s rumor — that was an inaccurate rumor,” Boehner said. 

Members said to be involved, according to reports from The Hill and other publications at the time, included former Rep. Tom DeLay (R-Texas), then-Majority Leader Dick Armey (R-Texas), former Rep. Bill Paxton (R-N.Y.) and Boehner. 

Asked repeatedly about Gingrich on Wednesday, Boehner demurred. 

“Newt’s been a longtime friend, but I’ve spent a long time this year avoiding getting involved picking winners and losers in the presidential contest,” Boehner said. 

House Majority Leader Eric Cantor (R-Va.) and House Majority Whip Kevin McCarthy (R-Calif.) have not endorsed a candidate. Conference Chairman Jeb Hensarling (R-Texas) has backed Texas Gov. Rick Perry. 

Romney surrogate Rep. John Campbell (R-Calif.) believes that many of his colleagues will soon endorse Romney. 

“For a while there it was either Romney or Perry. For a while it was Romney or [Herman] Cain — and I don’t think people knew them very well, including here [on Capitol Hill]. Everybody knows Newt here and everybody knows Romney,” Campbell said. “I think that Newt appearing to be the other alternative is going to motivate more members of Congress to endorse Romney.” 

There has been speculation this month that leadership members are trying to influence the race by having their lieutenants back Romney. Not so, according to leadership members and aides. 

“When I endorsed Gov. Romney, it was before Herman Cain even took off … and Speaker Gingrich himself described he was ‘left for dead’ … but he was the only one who didn’t know he was dead,” Walden said. 

Given the implosion of businessman Herman Cain, and Gingrich’s surge, lawmakers are “curious” as to who will be the next nominee because that person “is the biggest factor in their own races, beyond their control,” Rep. Tom Cole (R-Okla.) told The Hill. 

“There is an intense interest in who it will be, and a lot of discussion as to who would be better. A lot of people wonder, is there really a new Newt? A lot of people wonder, still, what’s Romney’s conservative, philosophical core? And then, which one is going to help or hurt me the most?,” the former House GOP campaign chief said.

But a number of well-connected lawmakers, who agreed to speak with The Hill on the condition of anonymity, say that Gingrich would implode in a general-election matchup.

“If Newt Gingrich is the nominee, we lose. That’s pretty much what everybody says,” one Republican lawmaker said, adding that the ex-Speaker “can’t win” against President Obama. 

Polls show that Gingrich has double-digit leads in three of the four early-voting states, with the exception being in New Hampshire, where Romney leads.

Members are wondering whether Gingrich can sustain his growing popularity. 

“He seems to be busting through at the right time. Is it sustainable?” the lawmaker observed.

Another lawmaker said Gingrich is connecting because of his vision. 

“Voters are hungry for somebody with positive ideas, and there’s nobody that can offer more positive ideas than Newt … in rapid-fire succession,” the legislator said.

Rep. Michael Burgess (R-Texas) said he endorsed the former Speaker, in part, because he was the only candidate who acted as cheerleader during the House GOP’s low points in late 2008.

{mossecondads}“There was a period of time right after the 2008 election when Republicans had collectively lost 50 seats in two election cycles and our viability was clearly in question and Newt was the one who continued to come to our conference and encourage us. He was maybe fulfilling the role of cheerleader at that point but I don’t recall seeing the other contenders down here telling us that cheerful persistence will pay off, and Newt did,” Burgess said. 

A House lawmaker elected in the historic class of 1994 explained that the country needs a leader who is “steady” — an attribute that Gingrich did not demonstrate in the late 1990s. 

“America needs steady … the time to be at the amusement park when the roller coaster ride is over,” said the member, who is poised to back Romney. 

Still, endorsements might not help Romney, Cole said. 

Cole said that “this [election cycle] is one where the American public, and particularly Republican primary voters, hold Washington and the Republican establishment in very low esteem. So why in the world, given that, do we think that people here are going to be able to influence the outcome how voters think around the country?”