Oregon Republican Sen. Gordon H. Smith, an affable moderate who waltzed through his 2002 re-election bid with a 16 percentage point victory, is now in the fight of his political life to return to the Senate next year for a third term.
A Rasmussen Reports poll released last week showed Mr. Smith trailing his Democratic challenger, Oregon House Speaker Jeff Merkley, 43 percent to 41 percent. If "leaners" are factored in, the race is tied with each candidate claiming 46 percent of the voters.
With Democrats holding a razor-thin 51-49 majority in the Senate, the national party has targeted Mr. Smith as one of the most vulnerable Republicans in the chamber, with the Democratic Senatorial Campaign Committee (DSCC) spending more than $700,000 on the Merkley campaign.
Democrats have accused Mr. Smith of abandoning many of his conservative principles so as to pander to the state's increasingly Democratic-leaning electorate. He initially backed President Bush's decision to wage war in Iraq, but withdrew much of his support shortly after the 2006 midterm congressional elections.
The Smith campaign also recently aired an unusual television advertisement in which the candidate boasted how he had worked with Democratic presidential candidate Sen. Barack Obama on energy issues.
DSCC spokesman Matt Miller said Mr. Smith "has tried to move to the left for the past year-and-a-half hoping that, in an election year, people will forget everything he did in his previous years of his term, and it just won't work."
But the Smith campaign says the senator has taken a largely independent, nonpartisan approach to legislating throughout almost two decades on Capitol Hill.
"Senator Smith has a 12-year history of reaching across the aisle to find bipartisan solutions to the most important issues facing Oregonians and Americans," said Smith spokeswoman Lindsay Gilbride.
The state's political climate, which has increasingly turned Democratic since 2000, might be Mr. Smith's biggest re-election obstacle. And with Mr. Obama comfortably leading presumptive Republican presidential nominee Sen. John McCain in many polls in Oregon, 2008 is shaping up to be a tough year for any Oregon Republican facing re-election.
"All those underlining factors means Smith [was poised to have] a difficult problem, as long as the Democrats nominated somebody who was a mainstream, credible candidate," Oregon State University political science professor William Lunch said. "And certainly Jeff Merkley fits that description."
Scott Rasmussen, president of the independent Rasmussen Reports polling firm, said that while Mr. Merkley's advantage is not statistically significant, it is noteworthy for an incumbent senator to receive such low levels of support at this point in a campaign.
"Any time an incumbent is below 50 percent, especially against a low-name recognition opponent, you assume that he's potentially vulnerable," Mr. Rasmussen said. "I don't think it's a surprise to anybody that it's a difficult year for a Republican, and it's especially difficult when you're running in a state that does not normally lean in the Republican direction."
Mr. Smith in recent months has held a comfortable lead in the polls, though he generally hasn't risen above the 50 percent mark. But after Mr. Merkley won a tough primary election in May against political activist Steve Novick, his poll numbers quickly ascended.
"It seems very dramatic, but it really isn't," said Mr. Lunch. "What it really shows is the core Democratic voting population - folks who are likely to show up and vote in November - have now learned that Merkley is their boy."
Ms. Gilbride called the Rasmussen poll results "questionable" because they relied on automated telephone calls from an "often dismissed pollster."
"We have for a long time considered this to be a competitive race. We're fully prepared for that," Ms. Gilbride said. "But it's a race we expect Senator Smith to win."
Mr. Smith holds a sizable fundraising advantage, as he raised $9.7 million by the end of the second quarter and had nearly $4.5 million in the bank as of June 30.
Mr. Smith also enjoys considerable personal wealth, which would allow him to tap his bank account to help finance his race if the national and state Democratic parties continue to pump money into Mr. Merkley's war chest.
Mr. Merkley raised more than $1.42 million for the three-month period ending June 30 - three times what he raised during the first three months of the year. He also had spent $2.2 million by the end of June and finished the quarter with $564,435 cash on hand.