LANSING, Mich. (AP) -- One of the sticking points holding up a possible do-over election in Michigan is a rule that would ban anyone who voted in the Republican presidential primary from voting again.
That ban would apply even to Democrats or independents who asked for a GOP ballot because Sen. Hillary Rodham Clinton was the only major candidate left on the Jan. 15 Democratic ballot.
To cast a ballot, voters would have to sign a statement that they hadn't voted in the GOP primary.
The effect of blocking those voters could be greatest on Sen. Barack Obama, since his supporters were more likely than Clinton's to have crossed over to vote in the GOP primary. The national party had punished Michigan for holding a primary before Feb. 5, stripping it of all its delegates. Clinton's name was on the ballot, but Obama and several other Democratic candidates took their names off to avoid angering other early voting states such as Iowa and New Hampshire.
Obama has also had more success than Clinton in attracting the votes of independents and Republicans in states where they're permitted to vote in Democratic contests.
Michigan's Republican primary drew 867,271 voters, including 18,106 who voted "uncommitted." The Democratic primary drew 593,837 voters. Clinton garnered 328,151 votes, or 55 percent; 237,762, or 40 percent, voted "uncommitted;" 21,708, or 4 percent, voted for Rep. Dennis Kucinich; 3,853, or less than 1 percent, voted for Sen. Chris Dodd, and 2,363, or less than 1 percent, voted for former Sen. Mike Gravel.
According to exit polls, 7 percent of GOP primary voters said they were Democrats and 25 percent said they were independents or something else. That means nearly 61,000 people who voted in the GOP primary were Democrats, while more than 217,000 were independents.
A group of Democratic leaders from Michigan are trying to set up a June 3 do-over Democratic primary so the state can get its delegates seated at the Democratic National Convention.
The Clinton campaign said Monday it would go along with another election, but the Obama campaign so far has said only that it's reviewing the proposal. Potentially at stake are a hefty 128 pledged delegates that Michigan had before it was punished by the DNC for moving up its primary date.
Michigan Democratic Chairman Mark Brewer says the party has the right - and the responsibility - to prevent non-Democrats from having a say in who the party's presidential nominee should be.
Michigan doesn't require voters to register by party in order to vote, so the political parties have to use other tools to stop crossover voting. Both parties are due to get a list of who voted in the Jan. 15 primary and which ballot - Democratic or Republican - they chose.
It's unclear if poll workers would use those lists to challenge anyone who had voted in the GOP primary.
Brewer said he regrets that some Democrats won't be able to vote in the second Democratic primary if one's held, but says there's nothing he can do about it.
"I regret that that might be the case, but it's a national party rule and we have no choice but to follow it," he said.
Even if more than 278,000 Democrats and independents would be barred from voting in a do-over primary, Brewer estimated that a June 3 election could still pull in at least 1 million and possibly 1.5 million people.
Obama supporters at the state Capitol in Lansing appeared determined to head off a vote on legislation creating a June 3 primary. But U.S. Sen. Carl Levin, one of four Michigan Democratic leaders trying to find a way to get the delegates seated, was calling lawmakers to urge a vote.
Figures are from exit polling for The Associated Press and television networks.