The Republican Party has been speed dating, racing through presidential prospects like a Hollywood starlet working her way through leading men. The fickleness suggests a party that doesn’t know whether its Tea Party heart or its establishment head should prevail in 2012.

Former Massachusetts Governor Mitt Romney was next in line, which is usually the right place to be in a Republican nomination contest. He checks some important boxes -- successful businessman, former governor -- and his conversion to conservative positions occurred far enough in the past that the phrase “flip-flop” no longer shows up in every story about him. He’s against health-care reform, though still dogged by the fact that he once was for it.

Trouble is, the base just can’t fall in love with the guy. To many evangelicals, the Mormon Romney belongs to a religious cult. To others, he’s a stiff -- and his open collar and un-gelled hair, newly responsive to the wind, don’t camouflage that fact. Romney has the demeanor of someone for whom every date is the first, occasioning stilted conversation and a desire to please. Eager to fit in, he’ll impulsively call your father “Dad” way before it’s appropriate.

No Passing Fancy

The party’s reluctance to embrace its putative front-runner has provided plenty of opportunity for political infatuation. The latest heartthrob is Texas Governor Rick Perry. A week after entering the race, Perry shot to a 29-to-17 lead over Romney in the Gallup Poll. Perry’s being treated by George Will, William Kristol and other prominent conservatives as if he’s more than a passing fancy. Yet evidence from the past six months suggests that Republican love burns brightly and fades quickly.

There was that spring fling with Donald Trump, for example. After he riled a crowd of conservative activists in Washington in February, the Manhattan huckster with an ego the size of the Taj Mahal (Las Vegas version) was eagerly embraced by the Republican base. Trump required more flip-flops than Romney to win them over -- suddenly finding God and guns while forsaking abortion rights and President Barack Obama, whose American birth he came to doubt publicly. By April, Trump was in first place in a Public Policy Polling survey, clocking in at 26 percent to Romney’s 15 percent.

Trump was a distant memory by the time Minnesota Representative Michele Bachmann burst on the scene. While Sarah Palin played hard to get, Bachmann jumped into the race with both heels, winning plaudits for her performance at a New Hampshire debate. Feisty, pretty, happy to let the U.S. default on its debt, she climbed from 6 percent to 14 percent in a month. By Aug. 13, the party activists who flock to the Iowa Straw Poll were sufficiently in love to give Bachmann a winning 29 percent of the vote in an eight-candidate field, knocking out Bachmann’s home-state competition, former Minnesota Governor Tim Pawlenty.

Bachmann Upstaged

Now Bachmann looks like a summer romance. Yesterday’s sweetheart can barely turn a Republican head, even with a promise of $2-per-gallon gasoline. At the Black Hawk County Republican dinner, held in Bachmann’s birthplace, Waterloo, Iowa, on Aug. 14, Perry upstaged her. While Bachmann was cocooned outside in a rock-star bus, her staff was inside adjusting the lighting to suit her cable-TV standards. Perry, meanwhile, worked every table, hugged every woman, slapped every back. After that, he still found time to clean his plate and her clock.

Perry out-Bachmanned Bachmann. He’s so big, so craggy, so Texas; he doesn’t just like guns, he packs heat. (He reportedly killed a coyote while jogging, though the details are sketchy.)

If Bachmann plays to the base, Perry channels it. He wouldn’t just vote against raising the debt ceiling, as she did. He threatens bodily harm to Fed Chairman Ben S. Bernanke and calls him “almost treasonous.” He is as radical as Bachmann, calling climate change a “hoax” and Social Security a “Ponzi scheme.” When he calls the nation’s capital a “seedy place,” he manages to sound folksy.

Not Morman

Is Perry another one-night stand? He’s a step closer to what the party needs -- a candidate who can excite the base (which powered the Republican win in the 2010 midterm election) without scaring the horses. His mix of executive experience, pro-business absolutism and public Christianity (translation: he’s not a Mormon) has mostly quieted Republican pleas for a white knight. An Associated Press-GfK poll released last week found that about two-thirds of Republicans and Republican-leaning independents are now pleased with the party’s presidential field, compared with just half in June.

There are aspects of Perry’s record that don’t rock the Republican base. He’s insufficiently agitated by homosexuality and, having built his career in a state that is more than one-third Hispanic, he’s downright soft on immigration. Romney fired an Anglo shot across Perry’s bow last week, pointing out that as Massachusetts governor he had vetoed legislation allowing children of illegal immigrants to attend college at in-state tuition rates. Perry had supported similar legislation in Texas.

As for the so-called Texas jobs miracle, Romney boasts that he has actually created jobs, unlike some unnamed competitor who has just “watched” them being created. For the rougher stuff, including Perry openly rewarding his campaign donors with state appointments and contracts, Romney’s probably hoping Bachmann will do the dirty work.

Romney would be grateful for a bruising fight between Perry and Bachmann, as long as the Texas governor doesn’t make a tidy lunch of Romney after polishing off Bachmann for breakfast. Romney’s best hope is that the dashing cowboy proves himself too conservative for the party to bet on in the general election. In that case, Republicans will have to tear themselves away from the one they love, and settle for the one who can win.

(Margaret Carlson is a Bloomberg View columnist. The opinions expressed are her own.)

To contact the writer of this article: Margaret Carlson in Washington at mcarlson3@bloomberg.net.

To contact the editor responsible for this article: Francis Wilkinson at fwilkinson1@bloomberg.net.