Four more superdelegates endorsed Sen. Obama Tuesday morning - leaving him about 30 short of the 2,118 needed to put him over the top, according to Politico's count.

Nearly 200 superdelegates have yet to make an endorsement, but most are expected to rush to Obama within hours or days.

The Associated Press, based on its projections of delegates Obama would earn Tuesday night as well as private and public commitments by superdelegates, declared that Obama had already effectively clinched the nomination.

Clinton campaign chairman Terry McAuliffe said Tuesday morning that once Obama gets the majority of convention delegates, "I think Hillary Clinton will congratulate him and call him the nominee."

 

But that doesn’t mean Clinton will concede defeat, acknowledge Obama as the undisputed nominee or formally end her campaign – and spokesman Howard Wolfson flatly denied a published report that Clinton would leave the race Tuesday night.

Clinton herself explained her position Monday in Yankton, S.D.

"Tomorrow is the last day of the primaries and the beginning of a new phase in the campaign. After South Dakota and Montana vote I will lead in the popular vote and Senator Obama will lead in the delegate count," she said.

"The voters will have voted and so the decision will fall to the delegates empowered to vote at the Democratic Convention. I will be spending the coming days making my case to those delegates. Their responsibility not only to the Democratic Party but to our country is to vote for the candidate who is best able to lead us to victory in November and best prepared to lead our country into the future."

Still, the Obama campaign was leaving nothing to chance. "We're still working the phones and we're still talking to people ... so we'll certainly have to wait until a little later tonight to see what the final tally is, but we certainly feel good waking up this morning," Robert Gibbs, Obama's spokesman, told CNN Tuesday.

Obama planned to end his evening with a rally in St. Paul, Minn. – in the arena where the Republican National Convention will be held in September.