Nominating Mitt Romney is sort of like taking grandma’s castor oil. Republicans are dreading the thought of downing their unpleasant-tasting medicine but worry that sooner or later they will have to.

By any logical political calculus, the former Massachusetts governor is an ideal presidential candidate. Ramrod straight, fit and well-educated, he knows all sorts of facts and figures and comes across like a cinematic chief executive.

At any other time, an informed technocrat like Romney would seem a dream candidate. Yet in the run-up to this election, the people are completely turned off by Washington’s so-called experts, such as Energy Secretary Steven Chu, Treasury Secretary Timothy Geithner, Attorney General Eric Holder – and increasingly Barack Obama himself.

As a former governor and presidential candidate, Romney has been fully vetted. In these racy times, Mormonism is viewed as more a guarantee of a candidate’s past probity than a political liability. So there is little chance in late October 2012 that a blonde accuser will appear out of Romney’s past, or that the New York Times will uncover a long-ago DUI charge.

The calculating Republican establishment believes Romney has enough crossover appeal to independents to beat a shaky Obama. It still has nightmares of Tea Party senatorial candidates Sharron Angle and Christine O'Donnell, whose 2010 primary victories led to inept campaigns and Republican losses in the general elections in Nevada and Delaware.

Although conservatives dub Romney a flip-flopper for changing positions on abortion, gun control and health care, the base knew all about those old reversals in 2008, when it nonetheless praised Romney as the only conservative alternative to maverick moderate John McCain. Apparently the party has moved to the right since then. Tea Partiers worry that, once in office, a moderate President Romney would prove a reach-out centrist – spending borrowed money like George W. Bush did on No Child Left Behind or the Medicare prescription drug benefit, thereby ruining for good the now-suspect Republican brand of fiscal sobriety.

The result of those worries is that Romney has become the process-of-elimination candidate. The Hamlet-like governor of Indiana, Mitch Daniels, hemmed and hawed and bowed out, as most knew he would. The charismatic and controversial Rudy Giuliani and Sarah Palin decided they were making too much money to go through another nasty political race.

If finger-pointing magnate Donald Trump was going to bet a campaign on Obama’s reluctance to disclose official documents, he would have done better to demand the release of the president’s mysteriously secret college transcripts and medical records rather than his birth certificate. In the debates, the audiences liked what former Sen. Rick Santorum had to say, regretting only that it came out of the mouth of Rick Santorum.

Rep. Michele Bachmann once soared as the anti-Romney and then crashed when 90 percent of her statements seemed courageous and inspired – but 10 percent sounded kind of weird.

Then came the most promising anti-Romney alternative, job-creating Texas Gov. Rick Perry. He looked as presidential as Romney but immediately proved even more wooden in the debates. His “brain-freeze” moments were made worse by occasional goofy explanations that seemed most un-Texan.

New Jersey Gov. Chris Christie and Florida Sen. Marco Rubio were always crowd favorites, and they’re certainly hard-charging conservatives. Yet at some point, both realized that their scant years in office were comparable, in theory, to the thin resume of Obama when he entered the presidency clueless.

Rep. Ron Paul’s shrill talk on fiscal sobriety is as refreshing as his 1930s isolationist foreign policy is creepy. Former Utah Gov. Jon Huntsman is a sort of weak Romney doppelganger, raising the same paradox that money, looks, polish and moderation this year are cause for suspicion, not reassurance.

Many like businessman Herman Cain’s straight-talking pragmatism. Yet more are worried that he might not know that China is a nuclear power, or that we recently joined the British and French in bombing Libya. By now, former Speaker of the House Newt Gingrich knows almost everything about everything. But lots of Newt’s original – and now abandoned – positions were as liberal as Romney’s. And not all that long ago, he seemed as brilliant and glib – and recklessly self-destructive – as his contemporary and antagonist, Bill Clinton.

To beat an ever-more-vulnerable Obama, Republicans keep coming back to someone who resembles a Romney, with strengths in just those areas where Obama is so demonstrably weak: prior executive experience as a governor, success in and intimacy with the private sector, a past fully vetted, and an unambiguous belief in the exceptional history and future of the United States.

In short, if Republicans are happy in theory that Mitt Romney could probably beat Obama, they seem just as unhappy in fact that first they have to nominate him.

© 2011 TRIBUNE MEDIA SERVICES, INC.