Republican presidential hopeful Mitt Romney scored a big win in Illinois on Tuesday night and looked to focus on Barack Obama instead of his GOP rivals -- and the Democrats are starting to fire back on him.

With 99 percent of the votes in, Romney had 47 percent while Rick Santorum was in second with 35 percent. Ron Paul took third with 9 percent followed by Newt Gingrich with 8 percent.

In his victory remarks on Tuesday night, Romney ripped into Obama.

Rick Santorum got a boost to his bid for the Republican presidential nomination last week when he won primaries in Alabama and Mississippi. A poll unveiled on Tuesday shows Santorum should be able to keep his momentum going down South though he is expected to lose the Illinois primary to Mitt Romney on Tuesday night. Santorum leads in Louisiana which holds its primary on Saturday.

The two leading candidates for the Republican presidential nomination -- former Gov. Mitt Romney of Massachusetts and former U.S. Sen. Rick Santorum of Pennsylvania -- hit the airwaves and each other on Tuesday.

Following their candidates lead from Monday, the Romney team hammered Santorum for comments that he made about the economy this week. For all those who still had questions, Rick Santorum has now provided a textbook example of what an economic lightweight looks like," said Gail Gitcho, a spokeswoman for Romney.

While Democrats plan to target U.S. Rep. Dan Webster, R-Fla., in November, the freshman congressman can count on the support of an old ally -- former Arkansas Gov. Mike Huckabee, best known for his bid for the GOP presidential nomination in 2008 and for his various media appearances, including a show on Fox News and a national radio show set to be launched later this year.

U.S. Sen. Marco Rubio, R-Fla., won national attention for his win in the 2010 election cycle and started generating buzz that he could wind up on a Republican presidential ticket in 2012 or down the road.

With Illinois holding its primary on Tuesday, Louisiana, which will have 46 delegates at the GOP convention in Tampa, is next in line with a primary on Saturday. This primary is shaping up to be the most important GOP presidential battle in the Pelican State since 1996, when Pat Buchanan effectively set himself up as the conservative alternative to Bob Dole by crushing Phil Gramm in the Louisiana caucus, which was actually held before Iowa in that election cycle.

It is way, way too early for this, but Chris Cillizza over at WaPos The Fix is offering his own version of the Sweet 16 for 2016-- with two prominent Florida Republicans in the mix for their partys nomination that year. U.S. Sen. Marco Rubio starts off as the top seed while former Gov. Jeb Bush is in the fourth seed.

U.S. Rep. Sandy Adams, already engaged in a contentious Republican primary fight against U.S. Rep. John Mica, announced on Monday she is backing restaurant owner Karen Harrington in the Republican primary to challenge U.S. Rep. Debbie Wasserman Schultz, the chairwoman of the Democratic National Committee.

Despite trailing in the polls (to Mitt Romney) in Illinois, which holds its primary on Tuesday, Republican presidential hopeful Rick Santorum is going all out on Monday to blitz the Land of Lincoln -- but plans to head home to Pennsylvania when the results come in.

Illinois will have 69 delegates at the Republican convention in Tampa -- and a poll released on Monday finds that Mitt Romney has a large lead in the primary set for Tuesday.

A poll of likely primary voters from Public Policy Polling, a firm with connections to prominent Democrats, finds Romney taking 45 percent, followed by Rick Santorum with 30 percent, Newt Gingrich with 12 percent and Ron Paul with 10 percent.

The poll of 506 likely Illinois Republican primary voters was takenMarch 17-18 and had a margin of error of +/- 4.4 percent.