Mitt Romney just had the kind of week that can give political reporters whiplash.

Romney slipped into a phone booth as Mr. Snooze and emerged as Superman, a suddenly dashing, and very daunting, challenger to President Barack Obama.

Just days ago, Romney appeared to be trailing helplessly behind the president nationally and in a host of critical swing states. The drawn-out series of primaries, and his own gaffes, had morphed Romney into an all-but-certain loser.

Then came this week and whooooooosh! Romney suddenly was in the hunt with a batch of new polls showing him closing the gap. Conservatives, so reluctant to embrace the man who gave Massachusetts a universal health care plan, were suddenly smitten.

A Washington Post-ABC News poll taken after Rick Santorum abandoned the GOP race found that 80 percent of conservative GOPers now held favorable views of Romney. That's record territory for the former governor.

There's little question that much of the new-found enthusiasm was centered not on Romney himself, but what he represents. He's not Obama.

For months now, I've thought that Romney would be competitive precisely for that reason. Romney's now the remedy for all things Obama for the most conservative GOPers, as well as the most liberal. That is precisely why Republicans are rallying to him after months of skepticism and open flirtation with so many others. They have no choice.

This week, the long, ugly run of primaries and caucuses suddenly were distant history. Republicans of almost every stripe were giving Mitt a fresh appraisal.

Republicans in these parts were doing the same. Four phone calls to GOP lawmakers who had been committed to other candidates, or who were undecided, produced this:

"I am fully backing Romney," said Kansas Rep. John Rubin of Shawnee. "He's an excellent alternative to the current administration."

Romney's "a strong candidate -- a lot stronger than John McCain ever was," said Missouri Rep. Jeff Grisamore of Lee's Summit.

Missouri Rep. Myron Neth of Liberty called him a "great counterpoint" to Obama.

Tim Golba, a former head of Kansans for Life, the anti-abortion group, showed the most reticence, but he's still on board: Romney's "going to be the nominee, and I'm definitely not voting for Obama, so I guess I'm going to have to."

Romney still has his problems, and GOP insiders still doubt his prospects. But the view from here is the race is going to be intense, negative and nip-and-tuck because Romney is, well, not Obama.