E.J. Dionne:

Watch out, Fred Thompson: By the time you get into the race for the Republican presidential nomination, Mitt Romney may have run away with your constituency.

And while Rudy Giuliani and John McCain have decided not to compete in next Saturday's Republican straw poll in Iowa, they now have a powerful interest in preventing Romney from turning what they had hoped would be a nonevent into a meaningful victory. Look for maneuvering from Romney's top rivals to strengthen former governor Mike Huckabee and Sen. Sam Brownback so they can dilute Romney's share of the vote -- and of the news.

Sunday's Republican debate on ABC's "This Week" suggested what has been obvious to many of the party's professionals: Of all the candidates, Romney has the most comprehensive strategy not only to win the Republican presidential nomination but also to position himself for next year's election.

I'm not so sure. Romney's abundance of flip flopping could easily come back to bite him badly, and undo that comprehensive strategy, if voters get the sense that he has no set of core consistent values.