WASHINGTON — President Donald Trump’s long-shot bid to overturn the election could become more far-fetched after Tuesday, when states with legal fights and recounts behind them can receive assurance that Congress must accept their electors.

Tuesday marks the so-called safe harbor deadline. Federal law requires that Congress recognize the slates of electors chosen by states that have resolved election disputes by this date.

The deadline comes as the Trump campaign has lost a barrage of court challenges in Michigan, Pennsylvania, Wisconsin, Georgia, Arizona and Nevada – each battleground states President-elect Joe Biden won – seeking to overturn the Nov. 3 presidential election.

Federal judges in Michigan and Georgia on Monday dismissed separate lawsuits from former Trump attorney Sidney Powell, an ally of the president, who tried to overturn results in those states with unfounded allegations of voter fraud.

More:’The people have spoken’: Federal judge rejects ex-Trump attorney Sidney Powell’s Michigan election lawsuit

“With each day that passes, particularly once the safe harbor deadline has passed, the possibility of changing the result becomes more and more remote,” said Rebecca Green, director of William and Mary School of Law’s election law program. “Without credible evidence to support the idea that there’s a problem, it just becomes less and less likely that anyone is going to disrupt the schedule as it unfolds in state statutes and federal law.”

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The safe harbor deadline, outlined in the Electoral Count Act of 1887, falls six days before the Electoral College meets Dec. 14 to formally cast votes for president based on the popular votes in each state.

Congress then meets Jan. 6 to count the electoral votes and certify a presidential and vice presidential winner. Biden is set to defeat Trump 306-232 in the Electoral College based on the certification of election results by states. 

Trump has refused to concede the election, falsely claiming the election was stolen by reciting conspiracy theories and baseless claims of widespread voter fraud.

It’s unclear how many states will meet the safe harbor deadline. Governors are required to communicate if they reached safe harbor status to the U.S. archivist. 

The safe harbor protection applies to states that have settled “any controversy or contest concerning the appointment of all or any of the electors.” States don’t have to meet the safe harbor deadline to have their electors counted. But for the states that do, their determination “shall be conclusive, and shall govern in the counting of the electoral votes,” the act reads.

“Meaning that Congress will not second-guess or question the state’s own final determination,” said Ned Foley, director of the election law program at Ohio State University School Law. “It gives the states the opportunity to chart its own destiny, if you will, with the respect to its electoral votes. Because if they make that final determination by that deadline, that’s the answer and Congress promises not to question it.”

The U.S. Supreme Court gave significance to the safe harbor deadline in 2000 when justices halted recount efforts in Florida so the state could meet the deadline in the race between President George W. Bush and Democrat Al Gore.

More:Alabama Rep. Mo Brooks says he will challenge Electoral College results

When electors from all 50 states and the District of Columbia meet Monday, they are obligated to vote for the candidate they pledged to support. Biden electors will convene in states Biden won, and Trump electors will convene in states Trump won.

When Congress counts the electoral votes on Jan. 6, it is historically a formality that reaffirms the Electoral College’s action.

But in Pennsylvania, more than 60 Republican lawmakers have called on the state’s congressional delegation to reject Biden’s victory in the state.

And U.S. Rep. Mo Brooks, R-Ala., said last week he hopes to “reject the count of particular states” like Georgia and Pennsylvania that had “flawed election systems.” Trump applauded the congressman.

Any effort to defy the votes from the Electoral College has virtually no shot of succeeding. It would be further guaranteed no success in states that meet the safe harbor deadline.