Barack Obama's wave of superdelegate endorsements puts him within reach of the Democratic presidential nomination by the end of the primary season on June 3 -- even if he loses half of the remaining six contests.

A Rasmussen poll taken in West Virginia on May 5 had Hillary Clinton leading 56 to 27 percent over Obama, with 17 percent undecided. The state, which holds its primary on Tuesday, has 39 delegates up for grabs and should be favorable ground for Clinton because of her success appealing to blue-collar voters who are prevalent in the state.

The Illinois senator has picked up 26 superdelegates in the past week. At that pace, he will reach the number of delegates needed to clinch the nomination -- 2,025 -- in the next three weeks, when delegates from the remaining primaries are included.

Obama has 1,871.5 delegates, including endorsements from party and elected officials known as superdelegates. Clinton has 1,697, according to the latest tally by The Associated Press. That leaves Obama just 153.5 delegates short of the number needed to win the nomination at the party's national convention this August in Denver.

There are 217 total delegates at stake in the six remaining primaries, in West Virginia, Kentucky, Oregon, Puerto Rico, Montana and South Dakota. Even if Clinton wins most of those delegates, Obama could reach the magic number by the time South Dakota and Montana vote on June 3.

Despite the bleak outlook, Clinton's campaign chairman insists the candidate will stay in the race until the last primary and predicts the New York Democrat will overtake Barack Obama in the popular vote.

“We are going through to June 3," Clinton Campaign Chairman Terry McAuliffe said on MSNBC Monday. "I can unequivocally tell you we are in until June 3.”