Washington ? It was not lost on anyone that the president-elect of the United States, riding the crest of his popularity, and the Democratic leadership of the U.S. Senate were outsmarted last week by a state politician who won his last election almost 20 years ago.

When and if Roland Burris claims the Senate seat from Illinois formerly occupied by Barack Obama, it will represent the greatest climb-down by an incoming president since Sam Nunn turned Bill Clinton around on the issue of gays in the military at the start of Clinton’s first term.

Fortunately for Obama, the voters are much more concerned with the economy and Obama’s effort to fix it than they are with the infighting over the Illinois Senate seat.

But politicians keep score on each other all the time. And, after a near-perfect month of transition operations, Obama has stumbled twice in two weeks, first being caught unaware by the investigation of Bill Richardson, his choice for commerce secretary, and then being outmaneuvered by Burris and his tawdry sponsor, Gov. Rod Blagojevich.

There are lessons for Obama in both incidents, starting with the importance of really knowing the other players in the game. Obama has had such a rapid rise in national politics that there are many key figures in both parties he barely has had time to size up.

But Richardson was a familiar fellow traveler on the 2007-08 presidential campaign trail, and Obama should have known that there were reports of a grand jury investigation of pay-for-play in New Mexico.

As for Blagojevich, Obama had to know, from his years in Springfield and Chicago, about the governor’s tawdry and ruthless reputation. But Obama seriously underestimated him.

Harry Reid, the Senate majority leader, got all 50 members of his caucus to sign a statement vowing they would never accept a Senate appointee from Blagojevich’s tainted hands, after prosecutors had published excerpts of wiretaps in which the governor had salivated obscenely over the way he could cash in on Obama’s Senate vacancy.

Obama personally endorsed that hard-line stand against seating anyone “tainted” by Blagojevich, issuing a statement that backed Reid and the others. But Burris was no more impressed than Blagojevich had been.

When the governor called the senators’ bluff, Burris launched a public relations blitz on television, insisting that it would be unfair to punish him for the governor’s alleged sins. Ignored for the moment was the fact that Burris had been rejected by the voters in three straight Illinois Democratic gubernatorial races and in one primary for mayor of Chicago. Had the Democratic-controlled Legislature ordered a special election, the odds against Burris would have been enormous.

But Burris’ ego is limitless. And it turned out that Reid had, once again, failed to do his homework or line up his votes. When Chicago black congressman Bobby Rush played the race card, questioning why anyone would stand in the way of Burris succeeding Obama as the lone African-American senator, you could feel a wave of anxiety go through Democratic ranks.

Soon, Sen. Dianne Feinstein, the outgoing chairwoman of the Rules Committee and a potential candidate for California governor next year, publicly called on Reid to relent. The Congressional Black Caucus weighed in on Burris’ behalf. By the time Burris sat down with Reid and Majority Whip Dick Durbin of Illinois, the fight was effectively over and Burris was gracious about accepting their surrender. Obama conceded as well, saying that if the Senate seated Burris, “then I’m going to work with Roland Burris just like I work with all the other senators.”

Obama justifiably figured that Burris was not worth a knockdown fight when he has so many bigger battles ahead of him. But the lesson that other politicians have drawn is that Obama may not always be able to count on his congressional allies and they may not be able to count on him. That is not the way he wanted to begin.