With Fred Thompson out of the race, some of his Tennessee supporters have signed on for Mitt Romney. I understand why they have; as has been noted before, the current crop of GOP candidates leaves much to be desired. I don’t think Romney was a terrible governor, and he does have an impressive resume. There are certainly worse candidates out there than him.

But having said that, I just can’t bring myself around to support Mitt Romney. The primary reason being you never know what you’re going to get. Romney has completely morphed at least four times over the past 15 years. He tends to support whatever positions tend to be most convenient for whatever office he is seeking at the time he holds them. I don’t like that.

It all started in 1994 with his race against Ted Kennedy for the US Senate. It was during this race that the first political incarnation of Romney was first glimpsed: Mitt 1.0. In this edition, Mitt Romney was an unabashed Massachusetts liberal. He favored abortion rights. He didn’t much like Ronald Reagan. Unfortunately for him, he did not unseat Kennedy.

A few years later, noting the failure for version 1.0, Mitt Romney launched Mitt 2.0. In this new and improved edition, Romney portrayed a centrist, pro-choice, pro-universal healthcare Republican. He emphasized his business experience, but also was careful not to veer too far right, as evidenced by his opposition to the Bush tax cuts.

It’s no secret that Mitt 2.0 was very successful in Massachusetts, at least for his first term. But Romney wanted to take his product national, and knew he needed to be retooled yet again in order to do it. So with some retooling, Romney relaunched himself as Mitt 3.0. This new and improved Mitt Romney was often at odds with previous editions, but consistency is far less important than power. Mitt 3.0 was an unlikely social conservative, staunchly pro-life and anti-gay marriage, completely at odds with Mitt 1.0, and, to a lesser extent, Mitt 2.0. But Mitt 3.0 did impress some influential people, and immediately emerged as a top contender for the GOP nomination. Yet this edition was never as popular with average Americans, as evidenced by its marketing failure in Iowa and New Hampshire, and yet again Mitt Romney had to pretend to take new positions.

And so it was that Mitt 4.0 was born. In this edition, Mitt Romney backs away from conservatism. Instead, he borrows heavily from Mike Huckabee and embraces economic populism. He promises to use the power of government to revive the Detroit auto industry. Mitt 4.0 was very successful in Michigan, but it remains to be seen how well it will sell elsewhere. Should Mitt 4.0 fail, look for Romney to relaunch Mitt 1.0, and position himself for a VP slot on a Hillary Clinton or Barack Obama ticket.

For me, it’s not Mitt 4.0 that is scary, although it is certainly worrisome. What concerns me is if Romney does get elected president and finds his poll numbers down. What will Mitt 5.0 look like? Given his history, it could be anything.

Cross posted at Tennesseefree