Newt Gingrich had a bad night Tuesday: After framing the Florida primary as the "Tea Party versus the cocktail party," he lost among tea party supporters, according to the exit polls that cable and broadcast networks sponsor as a consortium.

On the other hand, Mitt Romney had a great evening, rising from a nine-point deficit in the Rasmussen poll just nine days ago to a 14-point victory, sweeping virtually every demographic and picking up all 50 Florida delegates.

This was an important inflection point, but the contest won't end until one candidate starts consistently winning. That may be coming for Mr. Romney, but he must step up his game.

Mr. Romney's campaign has an estimated $20 million to spend while that of Mr. Gingrich has roughly $1 million. The Romney super PAC purportedly has more than $12 million while the Gingrich super PAC by my estimate might have around $4 million in its coffers. This disparity could prove decisive, and the Romney campaign will be tempted to simply rely on firepower and organization to bull through the calendar.

It might work: February has only two primaries (Michigan and Arizona, both on the 28th) and one debate (on the 22nd). Mr. Romney can duplicate his Florida strategy, where his campaign and super PAC outspent the Gingrich forces on ads by a ratio of 5 to 1 during the last three weeks.

But dangers lurk. While traditional news organizations have been balanced or slightly favorable in their coverage of Mr. Romney, the GOP blogosphere has been decidedly negative on him all January, pointing to continuing unease among conservatives.

Karl Rove is a former senior adviser and deputy chief of staff to President George W. Bush. He is a Fox News contributor and author of "Courage and Consequence" (Threshold Editions, 2010). To continue reading his column in The Wall Street Journal, click here.

Karl Rove joined Fox News Channel as a political contributor in February 2008. He also currently serves as a columnist for the Wall Street Journal. Mr. Rove helped organize the political-action committee American Crossroads. His latest book is "The Triumph of William McKinley: Why the Election of 1896 Still Matters" (Simon & Schuster, 2015). Follow him on Twitter @KarlRove.