On the final day of the primary race for Minnesota's U.S. Senate seat, most of the candidates stuck to low-key campaigning Monday.

Al Franken, the DFL-endorsed candidate, called for a new college tuition tax credit and held a young-voter rally at the University of Minnesota. The most visible of Franken's DFL primary opponents, Priscilla Lord Faris, the only other candidate to air campaign ads, spent Monday stumping in Duluth and across the Iron Range.

The Independence Party campaigns of Dean Barkley and Jack Uldrich, two of the better-known candidates in a crowded field, went publicly dark, with volunteers staffing all-important get-out-the-vote phone banks all day Monday.

The primary will determine which candidates will challenge GOP Sen. Norm Coleman in November.

The front-running candidates spent more time taking potshots at each other across party lines than concerning themselves with the other candidates on their own parties' ballots.

Coleman, facing only token opposition today, called for revamping the nation's energy policy as he headed back to Washington, where the issue is due to be debated soon.

Coleman held a news conference at his office in St. Paul to promote his support for an energy bill, saying that the bipartisan group behind it was looking for compromise that would allow offshore drilling while directing new revenue toward development of renewable fuels.

"It's the best deal on the table," he said of the bill backed by the so-called Gang of 16, the group of Democratic and Republican senators working for its passage. Coleman is one of the 16.

Franken's message of the day included a proposal to create an annual $5,000 tuition tax credit for all college students, which he said would help up to 10 million students nationwide.

"This is something worth fighting for," Franken said. "This is what the American dream is all about."

Backing student aid, or not

In a response to Franken, Coleman's campaign touted his attempts in the Senate to make college more affordable, while Franken said Coleman had a long record of cutting student aid.

The only other Republican on the primary ballot is Jack Shepard, who has a criminal record and has run unsuccessfully in several past elections while living in Italy.

The other candidates on the DFL ballot are Rob Fitzgerald, who was the 2006 Independence Party U.S. Senate candidate; Bob Larson; Alve Erickson, and perennial candidates Ole Savior and Dick Franson.

Seven candidates also are on the Independence Party (IP) ballot: Barkley, Uldrich, IP-endorsed candidate Stephen Williams, Darryl Stanton, Doug Williams, Bill Dahn and Kurt Michael Anderson.

Barkley and Uldrich, who served in the administration of former Gov. Jesse Ventura, issued a statement Monday saying they would make a joint appearance at the party's election- night party in Hopkins -- regardless of who wins.

"It shows we really are serious about unity," Uldrich said.

Meanwhile, Barkley, who served briefly in the Senate after the death of Paul Wellstone six years ago, picked up the endorsement Monday of former Democratic U.S. Rep. Tim Penny, who made an unsuccessful bid for governor in 2002 as the Independence Party's candidate.

Staff writer Patricia Lopez contributed to this report. Bob von Sternberg • 612-673-7184