President Obama is doing better among Ohio union members than he did in 2008, according to a poll conducted for the AFL-CIO, the nation's largest union group.

According to the poll, 70 percent of union members in the crucial swing state are backing Obama this time around, up from the 65 percent support they found in 2008. Exit polling from 2008 found union members backing Obama over Sen. John McCainJohn McCainBoston Globe mocked for 'bizarre' story about Romney waterskiing during healthcare debate Keith Ellison on McCain’s vote: How many others with brain cancer will lose coverage? McCain votes to advance ObamaCare repeal, replace after vowing to oppose MORE (R-Ariz.) by a 58 to 41 percent margin.

Partisan polling should be taken with a grain of salt and the poll does not indicate how enthusiastic union members are, but if these numbers are correct, it could be a crucial boost to Obama in the state. In 2008, 15 percent of voters were union members and 28 percent of voters were from union households, one of the higher levels in the country, according to exit polls.

Polls show Obama is doing much better with working-class white voters in Ohio than he is nationwide, a big reason why he's held a slight edge in most public polls of the state. The auto bailout is very popular there — one in seven Ohio jobs is tied to the auto industry — and last year voters in the state repealed a law Republicans and Gov. John Kasich (R) had passed that would have curtailed collective bargaining rights. Much of the ground effort on that measure was led by the AFL-CIO.

The poll of 408 AFL-CIO members who voted early or are certain to vote was conducted on Nov. 5, election eve, by Hart Research Associates. Its margin of error is plus or minus 4.85 percentage points.