If Mitt Romney meets what are now rising expectations for today’s 10 contests and collects momentum with state wins while racking up delegates, he’s still got a long slog to reach the 1,144 needed to claim the Republican nomination.

The Citizens United decision has changed the rules of engagement, by ensuring that whatever happens today, Romney’s three remaining challengers will continue to have the money to run. And as Rick Santorum and Newt Gingrich have competed to emerge as the anti-Romney—with each camp encouraging the other candidate to step aside—if the front-runner did knock one of the pair it could rebound to the advantage of the other.

While the Election Oracle shows Santorum continuing to lead the three in favorability rating (a measure of the tone of the online conversation about each candidate), the next month lines up well for Gingrich, who if he wins his home state of Georgia today as expected would be positioned for a third act in southern contests later this month in Alabama, Mississippi, and Louisiana.

To determine favorability ratings, the Election Oracle tracks 40,000 news sites, blogs, message boards, Twitter feeds, and other social-media sources to analyze what millions of people are saying about the candidates—and determines whether the Web buzz is positive or negative. That rating is weighted, along with the Real Clear Politics polling average and the latest InTrade market data, to calculate each candidate’s chances of winning the Republican nomination. (See methodology here.)