The Republican presidential race has been full of surprises, and there are more of them in the latest CBS News/New York Times poll out Tuesday that shows. The former Pennsylvania senator's support has doubled in five weeks, thanks in large part to support among social conservatives.
Ron Paul is in third place in the poll, ahead of Newt Gingrich.
But the new poll also finds 60 percent of GOP primary voters say it's still too early to decide whom they'll vote for, with many big states not holding their primaries for several more weeks.
On "CBS This Morning," CBS News chief Washington correspondent Bob Schieffer said the poll reveals that "Mitt Romney still has not sealed the deal with conservatives, a very large part of his party. They just don't believe he's a conservative. They're searching for their own champion, and this week it happens to be Rick Santorum.
"It is very interesting to watch the Santorum campaign unfold," said Schieffer. "Santorum, his wheelhouse has always been with conservatives, social issues. He has been the one who has been strongly against gay marriage; he's the one who's been strongly against abortion. You're already seeing where he's trying to get away from that and talk about economic issues."
Schieffer said the volatility in the race only underscores that the Republican Party has changed dramatically: "We keep talking about the Republican establishment, and who IS the Republican establishment? This is a very different Republican establishment than it was even four years ago. Certainly it's a very different Republican establishment than it was when Mitt Romney's father was the governor of Michigan. This is a party that has moved to the right, and it appears to me that a larger segment of it is more conservative than it used to be just four years ago than we may have even thought.
"And the underlined evidence of that it seems to me is, Rick Santorum is now leading. He may actually win Michigan. What does that do to the Romney campaign? It's hard to say, but it's not good!
"The other question is, what is Romney going to do now? My guess is he'll go back to the one thing that seems to work for him in this campaign and that is negative advertising," said Schieffer. "Let's not forget that at the beginning of all this way back there in Iowa, there was a time when Newt Gingrich was leading this pack. And then the next thing you know, Romney and his super PAC dumped just a load of negative advertising on Newt. He went down. He did not really come back until South Carolina.
The new poll also has bad news for Gingrich, a former front-runner. While Santorum's support has doubled, Gingrich's has been cut in half.
"I've pronounced him dead twice during that campaign and I've learned my lesson on this, but I think that is a serious blow to Newt Gingrich," said Schieffer.