Perhaps Mitt Romney's greatest vulnerability is the sense many voters and journalists have of him that his values are situational, that he'll take one position on an issue when it helps him politically and the opposite stance when that's advantageous.
The ideal competitor to a frontrunner with that kind of record then, would arguably be one who could boast of his consistency.
Tim Pawlenty may eventually be able to make that claim. But consistency isn't exactly the word that comes to mind right now with Pawlenty, the former Minnesota governor.
Pawlenty could be running the risk of causing whiplash in voters with his on-again, off-again attacks on Romney over what he called "Obamneycare."
After uttering on Fox News the killer attack-line on Romney for signing into law as Massachusetts governor health care legislation with an individual mandate, a model for the federal law, Pawlenty the next day refused to repeat the attack at the Republican debate.
This led many observers to attribute to assume he had gotten cold feet in the heat of the moment. That's not good place to be for someone who wants to be president.
Now Pawlenty is again going after Romney on healthcare.
This caused some politics watchers to wonder if there was a war for Pawlenty's soul within the campaign. It sounds like the war may be within Pawlenty himself.
Writing for The Caucus blog at the New York Times, Michael Shear reported that after his puzzling debate performance:
... Mr. Pawlenty made an appearance on Sean Hannity's Fox News cable show. He noted a desire to contrast the records of the candidates in a "respectful, policy-based way." But he also went straight for the jugular.
"I don't think we can expect new policies from someone who was involved in the development of 'Obama Care' who continues to defend it," he said.
There does seem to be something of the Dr. Jekyll and Mr. Hyde in that passage. Pawlenty practically seems to be trying to make Romney Obama's secretary of Health and Human Services while at the same time saying he wants to have a respectful debate about policy.
If Pawlenty keeps doing this as he tries to introduce himself to Republican voters, it could prove mighty difficult for those voters to figure out who the real Pawlenty is. Kind of the same problem many of them have with the frontrunner.
But maybe he's already made up his mind about with T-Paw we'll all be seeing from here on.
Mark Murray at NBC News' First Read blog had this on Friday:
Reached for official comment, Pawlenty spokesman Alex Conant tells First Read, "Tim Pawlenty screwed up in the debate. Mitt Romney screwed up health care in Massachusetts."