Several high-profile races are set to be decided in today’s primary, where many try to grab their party’s nod to take on incumbents and new opponents.

The Republican primary for the U.S. Senate tops the list as one of the most important contests in today’s primary, where car dealer Russ Darrow, state Sen. Bob Welch, businessman Tim Michels, and attorney Robert Lorge will seek the right to face Democratic Sen. Russ Feingold in the general election.

While the four candidates share a common disdain for Feingold, the Republicans have increasingly attacked each other in recent weeks despite a “unity pledge” agreeing to abstain from negative campaigning.

Welch questioned contributions Darrow and Michels gave to Democratic politicians in the past, prompting Darrow to urge his opponents to renew their “unity pledge” vows.

Some observers have said a candidate has yet to emerge from the pack in the Senate race.

“It seems like everyone says it will be one of two guys, but those two people are different for everybody,” Students for Bush chair Jessi Schober said, adding she decided only yesterday for whom she would vote. “I think one of the guys will run away with it, but right now, it’s too close to say who.”

The race for Wisconsin’s 2nd Congressional seat, where Democrat Tammy Baldwin has presided since 1999, pits Republicans Ron Greer and Dave Magnum against each other.

Greer is running on a socially conservative platform, where the former Madison firefighter opposes gay marriage, abortion, and supports a ban on stem-cell research. Greer hopes the third time is the charm in the 2nd District — he opposed and lost to Baldwin both in 1998 and 2002.

On the other hand, Magnum is making his first foray into a major political race.

The owner of several radio stations throughout the state, Magnum has voiced support for eliminating the “glass ceiling” inherent in some businesses.

Magnum says Baldwin has lacked flexibility during her years in Washington, D.C.

“As nice as [Baldwin] is, it’s her way or the highway,” Magnum said at a meeting of the UW College Republicans last week.

In the Wisconsin 16th Senate District, Democrats Mark Miller and Tom Hebl are vying for the spot soon to be vacated by Chuck Chvala. Chvala, who is facing criminal charges in connection with the Capitol caucus scandals, is not seeking reelection.

Elsewhere in the state, Senate Majority Leader Mary Panzer is locked in a primary battle with state Assemblyman Glenn Grothman. Grothman has criticized Panzer for not being a strong enough opponent of abortion.

Although the two Republicans are engaged in a fierce battle, the race will not hurt Republican unity, according to Schober.

“With two incumbents running against each other, there will be some division in the party, but I think it is causing people to examine the Republican Party and make people examine their own views.”