Minnesotans descended upon polling places at dawn's early light today to vote in a presidential election that could put the first black president in the Oval Office and to settle a U.S. Senate race pitting two bitter rivals.

At the top of Minnesotans' ballots: Democrat Barack Obama, attempting to become the first black president, vs. Republican John McCain. For Senate, GOP incumbent Norm Coleman is trying to turn back Democrat Al Franken and Dean Barkley's long-shot independent challenge.

It was difficult for Troy Williams to speak as he left his north Minneapolis polling place shortly after 8:30 a.m. Williams, 50, said he kept thinking about the significance of what he had just done. Making it even more special for him: He voted alongside his daughter who was casting her first presidential vote.

"I got emotional in there," Williams said. "The prospect of what could be ... it's mind-boggling. I never thought I would see this in my lifetime."

At 8 p.m. sharp, the head judge at one polling place on the U of M campus pulled the double doors shut tight, effectively ending election day. Those inside the Mississippi Room at Coffman Union were allowed to finish voting, but there were no lines outside. Tyler Young, 20, was the last voter out. He made it just in time, strolling a couple minutes before the judge closed the doors. Young said he had tried to vote earlier, but didn't have someone to vouch for him. He found a friend from another fraternity and returned after class, just before the polls closed.

Young said he was undecided until the last moment, when he finally chose Obama.

"I like both of them," said the self-described "Republocrat," but Obama's message of change won Young over in the end.

In St. Paul's Rondo neighborhood, the precinct at Maxfield Magnet School endured a brief power failure. The gym went black for about 30 seconds until dim backup lighting kicked in. As for the machine that collects completed ballots, it switched to a backup battery and pressed on uninterruption.

Outside, Baptist minister Rita Williams and her two teenage granddaughters set up a table with free coffee, hot dogs and pastries for voters.

"People were standing in line and kind of looking over here, and they didn't know that it was free," said Takayla Nelson, 14, one of the granddaughters. "They were kind of shy, but they kept looking. So we had to tell them, 'Don't you know it's free?' "

More than 600 people were lined up by 7 a.m. at Olivet United Methodist Church in Robbinsdale. The line ran from the building, to the parking lot and into the street. Police arrived to ensure traffic could pass.

A handful of disruptions surfaced in the first hours:

• In Minneapolis, technical trouble delayed the start of voting for about 30 minutes at North Point Health and Wellness Center in the 1300 block of Penn Avenue N.

• In St. Paul, a fire alarm about 30 minutes after the polls opened briefly halted voting at the busy Model Cities of St. Paul Inc. at University and Victoria avenues. Everyone was forced to wait outside until it was determined that it was a false alarm. Before voters were allowed back in to finish voting, they had to show their ballots and matching receipts.

• Also in St. Paul, a power failure hit the Dunning Recreation Center in the Merriam Park neighborhood. About 100 people were voting when the electricity went out about 8:20 a.m. after a car hit a utility pole nearby. Voting continued, and election officials took ballots to a secure location and entered them into the machines once power returned about 9:40 a.m., said Brad Meyer, a rec center spokesman.

Some voters at St. Helena Catholic Church in Minneapolis waited more than two hours to cast their ballot, but by mid-morning scattered reports suggested that the wait at many polling places was easing.

At the Bakken Library in Minneapolis' Linden Hills, the line had evaporated by shortly after noon. But at 11 a.m., at least 250 people were waiting in line to vote at Emerson School at 15th Street and LaSalle Avenue in Minneapolis.

Yet, even before the polls opened, many thousands of Minnesotans had already submitted absentee ballots -- a practice that gained steam like never before in this nation.

In Eden Prairie, first-time voter Andy Williams said the voting process went smoothly at St. Andrew Lutheran Church, where he cast his vote shortly after 4 p.m. He didn't have to stand in line, and poll workers explained everything, he said. Williams, 28, added that it was the presidential race that motivated him to vote this year.

"I just wanted to make sure I got my opportunity to get my voice heard," he said.

At the same polling place, Nate Liebherr faced some difficulties trying to cast his vote. He said election officials turned him away twice because he did not have proper identification. Liebherr, who said he moved to Minnesota last summer, showed up at the church around noon to vote. He had hoped that he could register there. Liebherr said he was told to go home and return with a utility bill to verify his address, but when he returned around 4 p.m. he was once again turned away and asked to return with a government ID. Liebherr, who serves in the military, was on his way home again to get his passport, and said he planned to come back try for a third time.

At the Dakota County Historical Society in South St. Paul, Lorna Redding, 68, from South St. Paul, and her daughter Dana Andersen, of West St. Paul, arrived at 6:20 a.m. to be first in line.

Andersen was wearing a "No-bama" T-shirt and was told to zip up her jacket to cover it. State law bans campaigning -- that includes buttons, clothing, etc. -- within 100 feet of a polling place entrance.

Redding also was asked to cover up her T-shirt. It was emblazoned with a picture of George Washington and read, "Cool ... By George."

Chris Zanmiller, a teacher, 56, and her daughter Mary Bohn, a grad student, also were among the early birds at the Historical Society.

"I've never come this early," said Zanmiller. She said she wanted to beat the crowds and to get a red "I voted" sticker to wear for her students.

Star Tribune staff writers Tim Harlow, Patrice Relerford, Bill McAuliffe, Deb Pastner, Richard Meryhew, Curt Brown, John McIntyre, Karen Paurus, Colleen Kelly, Dennis Buster and Paul Walsh contributed to this report.