WASHINGTON  In a year of mesmerizing political scenes, one of the most remarkable will begin to play out next week just down Constitution Avenue from the Capitol.

Senator Ted Stevens of Alaska, who as the longest serving Republican senator has prowled the corridors of Congress since 1968, will go on trial in federal court on charges of failing to disclose $250,000 in gifts and home renovations from a politically connected oil services company.

What makes the proceedings so astounding is not just that Mr. Stevens is a figure of outsize proportions in Alaska and the Senate. Or that the gifts came from a company headed by a longtime friend of Mr. Stevens at a time when the relationship between federal officials and the oil industry is under scrutiny. Or that his state, usually an afterthought in national elections, is now at the center of America’s political conversation because of the selection of Alaska’s little-known governor for the Republican presidential ticket. Or that he is the king of earmarks when such spending is itself on trial on the campaign trail.

No, on top of all that, the criminal proceedings will start about 40 days before Alaska’s voters must decide whether Mr. Stevens, 84, merits a seventh full term. His trial, near enough to the Senate so that he can excuse himself from the defense table to go cast votes if necessary, will substitute for his campaign in the closing weeks of the race.