June 18 (Bloomberg) -- Senator John Cornyn says ``war hero'' John McCain is ``clearly my choice'' for the presidency, citing his stances on national security, cutting wasteful spending and picking judges ``who believe in the Constitution.''

The Texas Republican sounded less enthusiastic about McCain last year when the Senate was considering an immigration bill: He got into an expletive-filled shouting match with him during a bid to reach a compromise, the Washington Post reported.

With Republican fortunes sinking under the weight of a prolonged war, a weak economy and one of the most unpopular presidents in history, a lot of former McCain foes are reaching out to him like a lifeline. That's because he's more popular among voters than is the Republican brand itself and may be the party's best hope for attracting independent voters.

``We've seen a lot of the grumbling quiet down because the stakes are very high,'' said Scott Reed, who served as campaign manager for Republican Bob Dole's 1996 presidential bid. ``He's going to have even more friends after the convention.''

During his two decades in the U.S. Senate, McCain, 71, has drawn more flak from fellow Republicans than any party lawmaker for bucking his colleagues on issues from immigration and campaign-finance overhaul to global warming, as well as for his fiery temper.

Now, party lawmakers, including Senators Mitch McConnell, the minority leader, Thad Cochran of Mississippi and Charles Grassley of Iowa, are professing their support.

`Stunningly Stupid'

McConnell's clashes with McCain go back a decade, first over a settlement of tobacco-related lawsuits and then campaign- finance legislation. In an October 1999 debate over election funding, the Kentucky lawmaker demanded that McCain prove his allegation that special-interest money was corrupting Congress, in what the New York Times called an ``unusually personal'' exchange. McConnell, 66, later called a Senate vote in favor of the McCain-sponsored legislation a ``stunningly stupid'' act.

Now, he says he's ``happy to support'' McCain.

For lawmakers, that support may be politically expedient. Recent polls show that while voters are much more willing to back an unidentified Democrat for president than an unidentified Republican, that changes when McCain's name is mentioned.

According to an NBC News/Wall Street Journal poll conducted June 6-9, 51 percent of respondents said they would prefer a Democrat for president, compared with 35 percent who wanted a Republican. When asked to pick a specific candidate, they backed Democrat Barack Obama over McCain by just 47 percent to 41 percent.

Santorum Flips

This isn't the first time Republicans have changed their tune about McCain.

Former Pennsylvania Senator Rick Santorum criticized McCain over his opposition to President George W. Bush's tax cuts in 2001 and 2003, and other issues including campaign funding and immigration. Still, when Santorum faced an uphill re-election battle in 2006, his old enemy came to the state to campaign for him. After Santorum lost, he resumed his attacks on McCain.

Earlier this year, Santorum, 50, told radio talk-show host Laura Ingraham that McCain has ``a horrible record in protecting us here at home,'' according to the Chicago Tribune.

By April, his line had changed again. In an editorial in the Philadelphia Inquirer, he wrote that McCain ``is clearly the candidate with the capacity, judgment, experience and will to confront America's enemies.'' McCain's decision to work with Democrats on issues such as the confirmation of judges ``was probably for the best,'' he said.

`Ideal Profile'

Antitax advocate Grover Norquist and party activist Ralph Reed, who were once targeted by McCain during an investigation of lobbyist Jack Abramoff, are backing the presumptive Republican presidential nominee.

``McCain was in many ways the ideal-profile candidate for the Republicans to nominate in 2008,'' Reed said in an interview yesterday, citing his appeal among independents.

For others, backing McCain is the best option available. Norquist said he now believes that McCain was misled by his staff in the Abramoff probe. And he said McCain's positions on taxes and other questions have improved.

``On the tax issue, he's moved to a position where we are very comfortable,'' he said in an interview. ``On spending, he's always been sort of better than Bush.''

While McCain opposed Bush's two tax cuts, he's since come around to supporting them.

Cochran's `Cold Chill'

Cochran, 70, who earlier this year told the Boston Globe that the thought of McCain becoming president ``sends a cold chill down my spine,'' later declared ``he would be the best president,'' according to Reuters.

Eight years ago, Representative Jeb Hensarling, a Texas Republican, was one of several people McCain targeted with a federal complaint for allegedly violating election laws in connection with an advertisement accusing the Arizona senator of being an environmental polluter.

Today, Hensarling, 51, is eagerly backing McCain for president.

``I can and will enthusiastically support Senator McCain as our Republican nominee,'' he said in a Feb. 11 statement after Mitt Romney dropped out of the race. ``He has earned our party's nomination, fair and square.''

To contact the reporters on this story: Hans Nichols in Washington at hnichols2@bloomberg.net; Kristin Jensen in Washington at kjensen@bloomberg.net

Last Updated: June 18, 2008 00:01 EDT