Tom Allen, long believed to be the likely Democratic nominee in the U.S. Senate race, racked up an impressive win over his primary election opponent in unofficial returns Tuesday.

With 497 of 615 precincts reporting, Allen held an insurmountable lead over Tom Ledue of Springvale 56,521 to 9,703 votes, or 85.4 percent to 14.6 percent.

Ledue, an educator who has not previously run for public office, faced long odds in his battle against Allen, a six-term congressman from Portland.

Allen will face Republican incumbent Sen. Susan Collins, who faced no GOP opposition Tuesday.

Because of Allen’s name recognition and sizable advantage in fundraising, it is likely that many Mainers were unaware that Allen faced a primary battle, political observers said.

According to the most recent federal campaign fundraising reports, Allen raised $3.87 million for his campaign and Ledue raised just over $42,000.

Ledue did not seek to criticize Allen in the race but instead campaigned on the premise that he could bring new ideas to Washington. Allen focused his efforts on opposing Susan Collins in November.

Shortly before 11 p.m. Tuesday, Ledue said he had just spoken with Allen and conceded the race. He said he would support Allen in the general election.

“We had a great conversation,” Ledue said. “We certainly want to see him win in the fall.”

Allen was complimentary of Ledue’s efforts.

“I’m very grateful for the support I’ve had tonight,” Allen said. “[Ledue] got into this race for the same reason I did. He wanted to see the country change and to be a part of it.”

In a separate e-mailed statement, Allen indicated he is looking ahead to the general election in November. He said that outcome likely will hang on voters’ beliefs about the war in Iraq, the economy and the country’s energy policies.

“This election is about important choices between competing sets of ideas and between failed policies or a new direction – the status quo or change, fear or hope,” Allen said in the statement. “I respect Susan Collins but she and I fundamentally disagree on the most important issues our country faces today.”

In conceding the race, Ledue said he felt good about the reception he received as he campaigned across the state.

“It’s been quite a journey,” he said. “I haven’t had one negative experience and I’ve talked to thousands of people. I’m very hopeful my message will make a difference before I’m all done with this.”

Ledue said he may take on an active role in promoting Allen’s general election campaign but that it was premature to say whether he would. He said his immediate goal was to catch up on sleep.

“I’m definitely ready for a nap,” he said. “We haven’t left anything in the tank.”