Gallup is reporting today that Barack Obama's lead over Hillary Clinton for the Democratic nomination has surged into double digits again:

Since just after the North Carolina and Indiana primaries, Obama has led Clinton nearly every day, including a stretch of double-digit leads in the May 18-22 Gallup Poll Daily tracking releases. Since then, his advantage had been slightly less, at five to eight percentage points, but is back to a 10-point lead in the latest data. (To view the complete trend since Jan. 3, 2008, click here.)

Just three primary contests remain, and news reports suggest that the dispute over the Michigan and Florida convention delegations will not be resolved in the best possible way for the Clinton campaign. The Democratic National Committee will meet this weekend and likely allow either half those states' delegates to attend, or the full delegations to attend, but with each member given half a vote. Thus, it is a near certainty that Obama will have clinched enough delegates to win the nomination under the current rules, and Clinton's only hope of winning the nomination may reside in lawsuits or a convention floor fight.