As Republican presidential candidate Mitt Romney transitions once again to an entirely new campaign pitch, the conservative Washington Times reports that some Republicans are “stirring” about whether Romney has any “core beliefs.”

Already dogged by a reputation for political shifts on the campaign trail, Mitt Romney is once again honing a new sales pitch to voters, with the former Massachusetts governor now casting himself as a real-world “conservative businessman” who is in sync with the tea party while eager to slap sense into the “career politicians” he blames for the nation’s problems. […]

“He’s a politician who would be perfectly comfortable in the 1960s when the media was controlled by a half-a-dozen political reporters and you could say one thing in one place and another thing in another place,” said Michael McKenna, a GOP strategist.

“But in this era, which is marked by lots of information and a real craving for authenticity, a guy like Romney has real trouble because I’m not really sure that he has any core beliefs except for two: He is mostly a free-market guy and he thinks he should be president of the United States.”

I don’t agree with McKenna much, but his assessment of Romney seems more than fair. Love Romney or hate him, the knock on him is entirely accurate: there’s no fundamental, unshakable core to this guy. He’ll shift with the winds, wherever they blow, in the hopes of advancing his ambitions. Those who trust that Romney will remain consistent are inevitably disappointed.

It’s precisely why Romney has flip-flopped on more issues than any politician in a generation. Indeed, if anyone can think of any major issues on which Romney has been consistent, I’d love to see the list.

In this most recent case, Romney isn’t just changing strategy. The fact that the one-time frontrunner would move away from his inevitability campaign is a sensible tactical shift given the circumstances.

Rather, what’s more interesting here is that Romney is overhauling his presentation of himself. We’re being introduced to Romney 5.0.

Romney 1.0 was an independent who distanced himself from Reagan and H.W. Bush.

Romney 2.0 was a moderate Republican, with liberal positions on social issues, who passed health care reform at the state level.

Romney 3.0 was a social conservative who cared deeply about the culture war.

Romney 4.0 was an experienced, above-the-fray voice for the GOP establishment who had no use or time for the party’s Tea Party wing.

Romney 5.0 loves Tea Partiers, signs right-wing pledges, brags about flying commercial, and hates “career politicians.”

I’m perfectly comfortable with politicians reaching new conclusions after earnest reevaluations, but there’s nothing even remotely sincere about Romney’s repeated reinventions.

Romney probably doesn’t want my advice, but I’d suggest he stop trying so hard to figure out the latest in a series of personas. Has he tried being himself? After all of his metamorphoses, does he even know who that is anymore?

When a politician changes so fundamentally, so often, shouldn’t he expect observers to question his integrity?

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.