Hillary Clinton may have drubbed Barack Obama in Kentucky’s Democratic primary on Tuesday, but a Gallup poll released the same day showed Democrats may finally be coalescing around the front-runner.

The poll, which was conducted before the primaries in Kentucky and Oregon, shows Obama opening a national lead of 55 percent to 39 percent over Clinton.

When you dig into them, the numbers underlying the poll look bleak for Clinton. Obama is both picking up strength among groups he was already strong with and eating into Clinton’s base of support. The poll shows that Clinton is losing voters from her key groups, including white working-class voters and women. It also shows Clinton and Obama tied at 47 percent among non-white Hispanics, and Obama leading Clinton by a point (47 to 46 percent) among those with a high school education or less. Obama is ahead among women voters 49 percent to 46 percent. Despite the weakness, Clinton still leads with Eastern voters and Hispanics. The poll has an error rate of plus or minus 3 percentage points and was conducted May 16 to 18.

The poll, and the results from Kentucky, lead to two major questions. First, could this shift in support be explained by the growing sense that Obama is almost assured of the Democratic nomination? Second — and vital to Democrats’ chances in November — can Obama continue to pull support from Clinton’s base, and can he then hold it in a general election matchup against John McCain?