Minnesota’s U.S. Senate candidates were locked in a close race Tuesday, with Democrat Al Franken hoping a Democratic wave would push him over the top and Republican Norm Coleman trying to hang on in a tough night for his party.

With 62 percent of precincts reporting, Coleman had a small lead of 42 percent to Franken’s 41 percent — a difference of about 23,000 votes out of almost 1.7 million counted.

Dean Barkley of the Independence Party was third with 15 percent, and exit poll data showed him pulling equally from Coleman and Franken.

Both Franken and Coleman spoke to supporters around 11:30 p.m., urging them to hang in for what they said could be a long night of counting votes.

“You’ve stood with me for 20 months; hang in with me for a few more hours and when every vote is counted, I believe we’re going to have a new U.S. senator for Minnesota,” Franken said.

Coleman also predicted victory. “I’m feeling very good right now,” he told supporters.

Coleman was struggling to hold onto his Senate seat against big Democratic gains nationwide, led by presidential winner Barack Obama. Several of Coleman’s fellow Senate Republicans were overtaken, with the GOP losing Senate seats in Virginia, North Carolina, New Hampshire, New Mexico and Colorado.

The photo finish in Minnesota’s Senate race came after months of intense campaigning and millions of dollars in ad spending.

Coleman and Franken each arrived at Election Day with a shot at winning. The pair traded narrow leads in the last few polls, with Barkley well back but a possible wild card.

In the campaign’s last days, Coleman was forced to respond to allegations in a Texas civil lawsuit that a donor and friend tried to funnel him $75,000. Win or lose, Coleman was likely to face continuing fallout from the allegations, which he denied.

For Franken, who made his name as a writer and performer on “Saturday Night Live,” the election was a referendum on 21 months spent trying to convince voters he had the stuff of a U.S. senator.

The candidates spent some $30 million attacking each other on the airwaves. Millions more poured into the race from the national parties and outside groups, leaving both men with high negatives in voters’ eyes.

Coleman portrayed himself as a pragmatist and a moderate who could get things done in Washington, and his stump speeches were filled with references to “reaching across the aisle.”

He characterized Franken as angry and unfit for public office, and hammered Franken for outrageous jokes and statements from his career as an author and satirist. Coleman also played up Franken’s blunders in filing his personal income taxes.

Franken’s path to Election Day began in February 2007, when he announced his candidacy live on his Air America radio show.

His celebrity profile and ability to raise cash made him a formidable opponent, and Franken vowed to win back a seat once held by the late Paul Wellstone. Franken promised to fight for the middle class, and criticized Coleman as too closely aligned with President Bush and special interests.

But Coleman led comfortably until late summer and early fall, when polls began to show Franken closing the gap. One poll showed a majority of voters thought ads attacking Franken were unfair; Coleman later announced he was dropping negative ads.

Franken also appeared to benefit from the public’s unhappiness over the Wall Street bailout legislation. Coleman supported the bill, and Franken said he would have opposed it.