UPDATED Apr. 2 at 9:30 p.m. with more details on the debate

The state Senate passed a bill Wednesday allowing Maine to participate in the National Popular Vote interstate compact. The bill will next go before the House for consideration.

The Senate was deadlocked over the bill, voting 17 to 17 in early March. Proponents of the bill vowed to lobby heavily until the tie could be broken.

It was a partisan divide, Democrats for and Republicans against, with the exception of Sen. Bill Diamond, D-Windham, who had voted against it.

The bill was able to pass today when Sen. Peter Mills, R-Cornville, jumped ship and voted with the Democrats, for an 18 to 17 final tally.

The NPV compact seeks to circumvent the Electoral College by getting states that join to commit their electorates to the winner of the national popular vote in the general presidential election. The compact wouldn’t take effect until enough states joined to make up a majority of the college.

Mills was against it at first because the current math gives Maine residents an advantage. With four electorates for the state, a vote in Maine is 1.7 times more powerful than the national average.

After the first vote on the issue, Mills said he thought more about the likelihood of presidential candidates coming to Maine. If polling shows one candidate with a clear advantage, he said, neither would have any incentive to come to the state.

If the winner was determined by the National Popular Vote, however, candidates would have incentive to come to Maine and the other small states to try and sway the undecided voters, Mills said.

Wednesday’s debate was a condensed version of the one held in March when the issue tied. Assistant Senate Majority Leader John Martin, D-Eagle Lake, talked about getting presidential candidates to spend time and money in the state. Sen. Ethan Strimling, D-Portland, drove home the point “one person, one vote.”

Republicans urged Mills to change his mind and vote against the bill.

“Maine gets attention because we split our electoral votes differently,” said Sen. Karl Turner, R-Cumberland. “If we’re in a compact and polling is done, and one candidate has a clear majority, Maine would get no attention.”

Sen. David Hastings III, R-Fryeburg, was absent for the first vote. He said Wednesday that he compact was a means of getting around the Constitution.

“Efforts should be made to amend it, not get around the Constitution,” Hastings said.

Common Cause was a lead proponent of the bill. Jon Bartholomew of Common Cause Maine issued the following statement after the vote:

“Electing our President using the national popular vote would ensure that a vote in Maine counted equally with a vote in Ohio or other swing states. It would also mean that the candidate who received the most votes would be elected president instead of sending a second-place candidate to the White House.”