After much public debate, a Maine law has brought the country closer to having the popular vote determine the winner of national presidential elections — but it’s unlikely that will happen before November or even at all.

Earlier this week, Maine Gov. Janet Mills allowed a bill to become law without her signature that would take effect once the National Popular Vote Interstate Compact is able to gather pledges for at least 270 electoral votes — the number of delegate votes needed to elect a president.

The movement has now gathered pledges from 17 states and Washington, D.C. — accounting for a total of 209 electoral votes.

The movement seeks to change the way a president is chosen, without a constitutional amendment, but experts say it’s unclear what happens when enough states have signed on. It’s unlikely this would happen before the 2024 election.

The National Popular Vote Interstate Compact seeks to guarantee that the candidate who receives the most popular votes in all 50 states and the District of Columbia wins the presidency.

When there are enough states pledging their popular votes to meet the 270 Electoral College vote threshold, all the votes in those states will be added up to a national count that determines the winner of the election. The National Popular Vote Interstate Compact says that will give each vote equal weight regardless of where a voter lives.

Five of the 46 presidents who came into office lost the popular vote, including Donald Trump most recently in 2016. The compact argues that not every vote is equal under the current system.

“Under the current system, a small number of votes in a small number of states regularly decides the Presidency. All-or-nothing payoffs fuel doubt, controversy over real or imagined irregularities, hair-splitting post-election litigation, and unrest,” the compact says on its website.

“In 2020, if 21,461 voters had changed their minds, Joe Biden would have been defeated, despite leading by over 7 million votes nationally.  Each of these 21,461 voters (5,229 in Arizona, 5,890 in Georgia, and 10,342 in Wisconsin) was 329 times more important than the 7 million voters elsewhere,” the compact says.

One expert says that everything that has to do with the Electoral College is controversial these days with a partisan divide on the issue. Many Democrats want to get rid of it, while more Republicans support it.

“If you look at all the presidential elections from 1992 through 2020, Republicans have won the presidential popular vote only once — and that was in 2004 when [George W.] Bush beat John Kerry in the popular vote. In every other election over the last 30 years, Democrats have won the popular vote, but because of the Electoral College, Republicans have gotten the presidency a couple of times despite losing the popular vote,” Darrell West, a Douglas Dillon chair in governmental studies at the Brookings Institute, told ABC News in an interview.

“Republicans feel the Electoral College advantages them now and so they don’t want to get rid of it,” West said.

West said the country currently only has a handful of swing states because of the Electoral College, so candidates spend most of their money on that small number of states.

“If we got rid of the Electoral College, candidates actually would campaign more broadly. They would visit more states because a vote in Illinois is the same as a vote in California,” West said.

Could this work?

Experts say the most direct way to change how presidents are elected is to amend the U.S. Constitution, but there doesn’t currently seem to be a feasible pathway without a consensus between both parties.

“Ultimately, there probably is going to have to be a constitutional amendment to get rid of the Electoral College, but everyone knows that’s not possible now for political reasons. It takes a very large majority in Congress as well as in the states to make any change to the Constitution. So what states are trying to figure out is, ‘Short of a constitutional amendment, are there ways to improve the Electoral College?"” West said.

But it remains unclear what happens when enough states pledge their delegates.

“There’s a lot of deep legal contestation over what happens next. I mean, in my judgment, I think it needs congressional consent,” Derek Muller, a law professor at Notre Dame Law School, told ABC News.

“If Congress fails to do that, I’m sure there will be litigation,” Muller said.

There are other legal questions, such as whether it would violate equal protections if the U.S. were to have different states with different rules for their elections and questions about whether a state has the authority to do this, Muller said.

“There are lots of open, contested questions … where I think the national popular vote, if it does hit 270, will immediately face a series of legal challenges,” Muller said.

West agreed that the legal situation is unclear.

“It’s not obvious what the status would be of these laws. States do have the authority to set election laws. But according to the Constitution, the electors to the Electoral College actually are free to vote the way they want,” West said.

“And so states can pass laws, but there haven’t been a lot of cases testing these provisions. And so it’s not clear how the Supreme Court would rule on this issue,” West added.

Muller said if a state sues another state, that case would go directly before the U.S. Supreme Court.

“It’s really unclear who would bring the challenge or where they would bring it. One of the more interesting wrinkles is that there is the possibility, when you’re dealing with a compact, you file directly in the United States Supreme Court so that could be a place where it goes. But again, I think there’s a lot of possibilities about the litigation strategy if it does hit 270 [pledges],” Muller said.

Has something like this happened before?

About 100 years ago, before the 17th Amendment was passed — which allows for the direct election of senators — states had begun shifting from legislatures choosing members sent by the state to the U.S. Senate to having “preference polls” for the public where they would signal who they wanted to represent the state.

“Some states — I think Oregon was one of the leaders among some others — would institute preference polls for the people for their senators. So they would hold an election that wasn’t binding, but it would just request, ‘Who do you want us to vote for?’ And then you got a sentiment from the people and the legislature could or could not follow that,” Muller said.

Later, those states — including Oregon — began binding themselves to the results of the preference polls, Muller said. He pointed to this as an analogy in which the states were trying to “convert legislative elections into a popular vote, even though there was no formal mechanism to do so.”

Eventually, the Constitution was amended to make Senate seats elected by popular vote.

West argues that the direct election of senators did require the constitutional amendment to go into effect.

“And that was 100 years ago, when the political times were less polarized than what we have today,” West said.

Some states unsuccessfully tried to implement term limits for members of Congress about 20 or 30 years ago, Muller said. The Supreme Court said that was unconstitutional in 1995.

“So Missouri tried something a little more creative, which was to say, ‘OK, we’re going to ask all candidates to take a term-limits pledge, and we’re gonna print if they violated their pledge, we’re gonna put that on the ballot, or if they declined to support the term-limits pledge … we’re gonna print that on the ballot,"” Muller said.

“The goal was to say, ‘Well, we’re not keeping you off the ballot, we’re just telling everyone whether or not you’re adhering to term limits,"” Muller said. “And the Supreme Court said, ‘Well you can’t do that either."”

Copyright © 2024, ABC Audio. All rights reserved.