(CNN) Maine's lawmakers passed a bill that would give the state's electoral votes to the presidential candidate who won the national popular vote, taking a step toward becoming the 15th state to enact such a law.

The Maine Senate voted 19-16 Tuesday to join the National Popular Vote Interstate Compact, which would give all committed states' electoral votes to the winning popular vote candidate should the group accrue the 270 votes necessary for a majority.

California, Colorado, Connecticut, Delaware, Hawaii, Illinois, Maryland, Massachusetts, New Jersey, New Mexico, New York, Rhode Island, Vermont, Washington state and the District of Columbia have all committed to the pact. The most recent addition, New Mexico, put the total at 189 electoral votes.

Maine is currently one of two states, along with Nebraska, that splits its electoral college votes instead of adhering to the winner-takes-all policy most states follow. Should the Maine House pass and Gov. Janet Mills sign the bill, Maine would contribute another four votes towards the 270. CNN has reached out to Mills on whether she intends to sign the bill.

Former Maine Gov. Paul LePage alleged earlier this year that if such a law were to pass, "white people will not have anything to say."

"What would happen if they do what they say they're going to do, white people will not have anything to say," he said. "It's only going to be the minorities that would elect. It would be California, Texas, Florida."

The Electoral College effectively results in voters casting ballots not for their desired presidential candidates, but for 538 electors who in turn select candidates. The mechanism clinched President Donald Trump the 2016 presidential victory despite Democratic nominee Hillary Clinton winning a popular vote majority by nearly 3 million votes.

And the issue has already reached the 2020 race. Presidential candidate Elizabeth Warren said during a CNN town hall in March that she supported doing away with the electoral college.

"My view is that every vote matters, and the way we can make that happen is that we can have national voting and that means get rid of the Electoral College -- and every vote counts," she said. Other candidates have since taken up the same position.

CORRECTION: This story has been updated to correctly reflect that Maine and Nebraska are the two states that split electoral college votes.