Bill Kristol, not exactly a Romney fan, begins to come around:
Rick Santorum is entitled to stay in the race, and to offer voters in the remaining states an alternative. But it's probably time for him to do what Mike Huckabee did in similar circumstances in 2008—basically to stop attacking the almost inevitable nominee, and instead to adjust his own message going forward to a positive and issues-based one.
Conn Carroll agrees:
That is fair. Santorum fought hard to establish his last-not-Romney-standing status. He has earned the right to continue building his post-election brand in much the same way Huckabee did in 2008. He’ll get his own book deal, his own Fox News contract, and maybe even his own show. But he will not be the nominee. And he needs to start acting like he knows that now.
Jonathan Tobin, on the other hand, bets that the race will only get uglier:
[A]s Santorum made clear in his speech last night, a win in his home state — even if it is narrow and even if he doesn’t actually win a majority of the delegates at stake there — will be used as a launching point for continuing an insurgency whose aim will be more to tear down Romney than to actually supplant him as the nominee. … That means the next three weeks are likely to be the nastiest yet in what has been a long, nasty Republican race. Romney knows he must squelch Santorum now while he has a chance to humiliate him at home or else face a difficult couple of months that will undermine his chances of victory in the fall.
Matt Lewis adds:
Santorum’s goal, of course, is to make it to May, where he could possibly win states like Texas and North Carolina. But can he make it to the south after having been humiliated in what is considered his home state? He may be up in the Pennsylvania polls today, but he was also up in Ohio and Wisconsin, too — before he was vastly outspent and outmaneuvered. What is more, it’s not like Santorum is the Keystone State’s most beloved favorite son. He’s from Virginia, he lives in Virginia, and he lost his last re-election campaign in Pennsylvania by a huge margin.
(Photo from the Meh Romney tumblr, which captions, "This is the lonely cabin where all of Romney’s ideas go to die.")