What to watch for Tuesday in politics

Phil Pruitt

There are three GOP nomination contests today. Voters will gather for caucuses in Minnesota and Colorado, and head to the polls for a primary in Missouri. Networks could project winners in Minnesota and Missouri as early as 8 p.m. EST and 9 p.m. EST in Colorado. Delegates at stake Tuesday: 76. Needed to win the nomination: 1,144.

Mitt Romney will spend the day in Colorado, Ron Paul in Minnesota, and Rick Santorum will zip around to all three states in play. Newt Gingrich, however, is headed to Ohio, where early voting begins ahead of the March 6 primary.

Back in Washington, President Obama will host the second White House Science Fair. In remarks to students, educators and business leaders at 11:25 a.m. EST, he will emphasize on'the importance of science, technology, engineering and math education.

Up on Capitol Hill, a Senate-House conference committee will meet at 10 a.m. EST to continue trying to work out a plan for extending the payroll tax cuts, which expire at the end of the month. And later in the day, at 2:30 p.m. EST, the Joint Economic Committee will hold a hearing on the same issue.

Federal Reserve Chairman Ben Bernanke will be on the Hill, too, to testify before the Senate Budget Committee on monetary and fiscal policy.

And the House convenes at 10 a.m. EST with a bill banning members of Congress from insider trading on its agenda. The bill passed the Senate last week.

And then there are these two items: At 6 p.m. EST, actress Scarlett Johansson and Vogue editor-in-chief Anna Wintour will host "Runway to Win," a fashion fundraiser for Obama. And Jon Huntsman will be a guest on "The Tonight Show With Jay Leno" 11:35 p.m. EST.

Sources: Yahoo! News, ABC News and Associated Press