Former Massachusetts Gov. William Weld is suing to overturn the state's winner-take-all system for presidential elections, as part of a nationwide campaign to change how the United States chooses its chief executive.

The suit, filed Wednesday in federal court in Boston, alleges that the system -- in which presidential electors are legally obligated to support the candidate who receives the most votes in the state -- disenfranchises supporters of losing candidates and is unconstitutional.

Weld's suit is part of a broader effort to establish proportional voting across the 48 states which currently use a winner-take-all system. Suits have been filed in Massachusetts and California, both heavily Democratic, and in the Republican-majority states of Texas and South Carolina.

"The predominant method in America for counting votes in presidential elections violates the United States Constitution; it also distorts presidential campaigns, facilitates targeted outside interference in our elections, and ensures that a substantial number of citizen voters are disenfranchised when their votes are tallied in early November, only to be discarded when it really counts in mid-December," the suit claims.

Gov. Charlie Baker, a former Weld administration official, and William Galvin, the state's elections chief, are named as defendants in their official capacities in certifying and administering federal elections.

Weld, who served as governor from 1991 to 1997, was the vice presidential nominee on the 2016 Libertarian Party ticket. Richard Lyman, also a former Weld administration official who currently works with Weld at the lobbying firm ML Strategies, and Robert Capodilupo, a Republican voter, are also named as co-plaintiffs.

At least 38.1 percent and up to 58.4 percent of Massachusetts voters supported losing candidates in the last eight presidential elections, according to the suit. Those voters had their Fourteenth Amendment and First Amendments rights violated by the winner-take-all (WTA) system, the suit claims.

"Their votes were completely irrelevant to how the Electors representing Massachusetts voted in the Electoral College. WTA thus treats Massachusetts citizens who vote for a losing candidate in an arbitrary and disparate manner in clear violation of the principle of 'one person, one vote,' " the suit says. "In addition, WTA violates the First Amendment because of the burdens that it places on the right of association and on the right to have a voice in presidential elections through casting a vote."

The suit also notes how the current system relegates strongly partisan states, like Massachusetts and Texas, to the campaign back-burner.

"As a result, candidates from major political parties rarely hold campaign events in Massachusetts once they are selected by their parties in the primary," the suit says. "This results in a reduced opportunity for all Massachusetts voters to interface with and petition the candidates for major political parties in person, and 'to express their ideas, hopes, and concerns to their government and their elected representatives' as is also protected by the Petition Clause of the First Amendment."

Two election law experts interviewed by MassLive threw cold water on the lawsuit's chances.

"It's an extreme long shot because the constitution gives state legislatures the power to set the rules for choosing presidential electors," said Rick Hasen, an election law expert and University of California, Irvine professor of law and political science.

The suit makes a compelling case for election reforms, University at Buffalo election law professor James Gardner said in an interview. But he said it's almost certainly doomed to fail in the courts.

"The Supreme Court has specifically rejected the idea that proportionality of results is necessary to ensure equality of voting influence for political minorities," Gardner said.

The suit acknowledges that the Supreme Court has weighed in on the issue before, upholding a lower court opinion that found winner-take-all voting constitutional in a 1968 case.

But the suit argues that the Supreme Court's decision in Bush v. Gore -- in which the court overturned Florida's year 2000 recount procedures on the principal of 'one person, one vote' -- invalidated the 1968 ruling, giving hope for a new legal challenge.

Hasen credited the suit for the novelty of its argument, but noted that Bush v. Gore, which put the court in the highly unusual position of ending a presidential election, was a "radioactive" decision that has never since been used as Supreme Court precedent.

"It would be a pretty radical change in how we think about the nature of the electoral college," Hasen said.

If nothing else, the suit -- which is backed by a coalition of attorneys, including Al Gore's 2000 election litigator David Boies -- could bring needed attention to the role that winner-take-all voting plays in American elections, according to Gardner.

Until the early 20th century, state legislatures would often flip between winner-take-all and proportional voting to secure a partisan advantage, he said. Now, activists are focused on a different problem with the system -- how it discounts the votes of millions of Americans who are political minorities in their states, from Democrats in Alabama to Republicans in New York to Libertarians and Green Party supporters everywhere.

"It's a nicely done complaint. Nice try, I guess, is what I would say," Gardner said. "It makes a very strong case for a policy change. It would be great that every state did this, I don't disagree, but I think the constitutional basis for it is thin to vanishing."