Since he began running for the U.S. Senate 17 months ago, Democratic Rep. Tom Allen hasn’t been able to get close enough in the polls to seriously threaten the Republican incumbent, Sen. Susan Collins.

But with just over four weeks to go before Election Day, the campaign is being transformed by the events on Wall Street and in Washington.

The implosion of the nation’s financial sector has given Allen an opportunity to redefine Maine’s U.S. Senate race around the economy, an issue that nationally is benefiting Democrats, according to political observers and campaign operatives.

Whether Allen can make up the double-digit gap that polls suggest separates him and Collins remains to be seen. Experts believe Collins so far has effectively blunted attempts by Allen to blame the economic crisis on Bush administration policies that Collins supports.

The financial crisis, though, appears to be helping the Democrat at the top of the ticket, Barack Obama, and further damaging Bush’s popularity. That could make Collins vulnerable because she has voted with Bush on some big issues, such as the war and tax cuts for the wealthy, said Patrick Murphy, president of Pan Atlantic SMS, a Portland market research company.

“People are angry,” he said. “It creates an opening for Tom.”

Recent national polls of likely voters indicate Obama has taken a five- to nine-point lead over Republican nominee John McCain.

Moreover, 66 percent of Americans now disapprove of President Bush’s handling of the economy, according to a recent CBS-New York Times poll. That’s a new low for the president.

Until recently, Collins had been running commercials highlighting her service to constituents. But she changed tactics last week and took on the Wall Street crisis.

In an ad aimed at blunting the impact of Allen’s new commercial, Collins is shown telling supporters about her position on the $700 billion bailout bill that the Senate passed Wednesday. The narrator says, “It’s a time for bipartisanship. America faces a grave threat to our financial system.”

Roy Lenardson, a Republican strategist, said the economic crisis would only strengthen Collins’ position because most Maine voters see her as a moderate who can work across party lines.

“In the middle is where things get done,” he said. “The only way to fix things is working together.”

Indeed, Collins’ ability to distance herself from Bush may prove helpful to another candidate trying to do the same thing – John McCain.

The McCain campaign is ramping up efforts in Maine, one of only two states that splits its electoral votes. A CNN report notes that Collins has a big lead and a strong organization.

What makes this race different from others, said Collins spokesman Kevin Kelley, is that while both Allen and Collins have been in Congress for 12 years, she is the only one who has built a solid reputation for working with both parties to get the job done.

“Senator Collins is not interested in scoring partisan political points,” he said. “Instead, her focus is always on doing what’s right.”

Allen spokeswoman Carol Andrews said the financial crisis helps “crystallize” for voters the fundamental difference between the two candidates.

“Tom has been working for the middle class, and Susan Collins supports failed economic policies that have left the middle class behind,” she said, adding, “Bipartisanship doesn’t make everything right. You have to take a stand.”

The economy dominates

It is difficult to judge whether the financial crisis has changed Mainers’ opinions.

In the most recent poll on the Maine race, Allen trailed Collins by 16 percentage points. The SurveyUSA poll of 820 registered voters had a margin of error of 3.8 percentage points.

But that poll was done on Sept. 22 and 23, before the scope of the economic crisis became apparent to many voters.

While the crisis presents an opportunity for Allen, he will have a hard time pitching his message to voters because it may get lost in the blitz of campaign advertising that occurs in the final weeks before the election, said Dennis Bailey, a Democratic political consultant not involved in either campaign.

He said Collins’ recent commercial on her bipartisan efforts was especially effective, and that Collins has a large campaign war chest with which to finance a wave of similar commercials and defend herself against Allen’s charges.

“Even though Allen has an opening, it’s really tough to put a dent in her, and she will fight right back,” he said. “It will come down to how closely you can tie Susan to the Bush administration, and the Bush administration has never counted on Collins as an ally. It will always be hard to draw that connection.”

When he first began his campaign, Allen’s top issue was the war in Iraq. While Allen also talked about his disagreements with Collins over tax policy, economic issues appeared to be second place. That’s no longer the case.

One thing is clear: The economy will dominate the campaign for the remaining weeks for both candidates, said Marvin Druker, a professor of leadership studies at the University of Southern Maine.

The crisis, he said, is “so vast and dramatic, any candidate running for office has to respond to it.”