• The Wisconsin primary Feb 19. will play a role in shaping the presidential nomination
• McCain leads the Republican Party's presidential nomination race after a big day Tuesday
• Clinton and Obama are in a tight race that should lead to Wisconsin primary
• Campaigning in Wisconsin will be a major factor in winning the state

Wisconsin voters, mark Feb. 19 on your calendar.

That's the date of the Wisconsin primary, when residents can vote for the Republican or Democratic presidential nominee.

And Wisconsin will most likely have a voice in deciding who the presidential nominees will be, said Charles Franklin, a University of Wisconsin-Madison political science professor.

The largest Super Tuesday in the nation's history—with 24 states holding primaries or caucuses—is over, but the nomination races are still mainly undecided, he said.

Sen. John McCain (R-Ariz.) came out leading the Republican Party's contest Tuesday, but he hasn't sealed his bid yet, Franklin said.

Meanwhile on the Democratic side, Sen. Hillary Clinton (D-N.Y.) and Sen. Barack Obama (D-Ill.) are still neck-and-neck in the race for delegates. As of Tuesday morning, Obama had 34 pledged delegates while Clinton held on with 21 pledged delegates, according to The New York Times. As Super Tuesday results continue to be tallied, those pledged delegate counts will rise. Other news organizations, such as the Associated Press, report much higher delegate counts but those are largely based on projected, non-binding delegate votes.

The Democratic candidate will need 2,025 delegates to receive the nomination.

The Democratic race has remained tight and Franklin said it should stay that way until the Wisconsin primary.

The only other Democratic caucus on Feb. 19 is in Hawaii. This will direct the presidential hopefuls toward Wisconsin, Franklin said.

"We'll have the undivided attention of the candidates," he said.

A political science professor at University of Illinois, Urbana-Champaign, Charles Gaines, said Wisconsin's Democratic primary "is up for grabs." The race could be down to whoever campaigns more heavily in the state, he said.

Janet Boles, a Marquette political science professor, said Wisconsin will be in the spotlight but won't be "the king-maker or queen-maker."

Primaries in Pennsylvania, Ohio and Texas, which all come after Wisconsin's and have a combined 577 delegates up for grabs, will have a much larger role in deciding the presidential nominees, she said.

Boles said Obama should win in Wisconsin because of his proximity to and ability to win many Midwest states. She said McCain looks to be the frontrunner in Wisconsin because of residents' religious differences with former Arkansas Gov. Mike Huckabee.

But Franklin said with McCain dealing no "knockout blow" to Republican candidates Tuesday, Huckabee could be rejuvenated and continue the fight for his party's nomination. Former Massachusetts Gov. Mitt Romney, however, could be on the verge of dropping out after poor results, he said.

Gaines said McCain was helped by some states' winner-take-all format, in which the candidate who receives the majority of the vote wins all the state's pledged delegates, rather than dividing the state's delegates proportionally based on popular vote percentages.

McCain won six states with the winner-take-all format, Romney won two and Huckabee won one Tuesday.

As of Tuesday, McCain had 273 pledged delegates, Romney owned 63 pledged delegates and Huckabee touted 25, according to The New York Times. As with the Democrats, those counts will rise as results continue to trickle in.

The Republican candidate will need 1,191 delegates to win the nomination.

Gaines said both Huckabee and Romney need to pull off a small miracle to win the Republican nomination.

He said the Obama-Clinton race has remained close because no Democratic primaries have a winner-take-all format.

The media puts an emphasis on winning states, but what really matters is how many pledged delegates a candidate has, Gaines said. While Obama won the popular vote in Missouri, he and Clinton will split the Show-Me state's 72 pledged delegates, he said.

Wisconsin Gov. Jim Doyle has begun campaigning for Obama in Wisconsin. He held events in Green Bay and at the University of Wisconsin-Oshkosh yesterday and is holding events today at Chippewa Valley Technical College and the University of Wisconsin-La Crosse.

For the Democrats, primaries and caucuses in Louisiana, Nebraska, Washington, Maine, Washington D.C., Maryland and Virginia all come before Wisconsin's primary.

For the Republicans, primaries and caucuses in Louisiana, Kansas, Washington, Washington D.C., Maryland and Virginia all precede Wisconsin's.