Miles Parks for NPR:

Last week, Pennsylvania’s Supreme Court said ballots that are postmarked on or before Election Day will be counted so long as they’re received within the next three days.

And a Michigan state judge last week also ruled that absentee ballots postmarked by Nov. 3 can be counted if they arrive up to two weeks after Election Day.

The developments could mean more votes will count in the states that would have otherwise been disqualified, but it also could mean a longer wait before a definitive winner is announced in the closely contested battlegrounds. An NPR analysis of absentee ballot rejections during the presidential primaries this spring found that at least 65,000 ballots were rejected for arriving late.

“The broad upshot of this is that in Wisconsin, which is already a very closely watched state, we’re going to be watching it for about a week longer before the results can be known,” said Eddie Perez, an election administration expert with the OSET Institute.

Even with the changes, Perez noted, North Carolina is in a slightly better position to have at least some of the mail voting results available quickly, because the state allows officials to begin processing received mail ballots two weeks before Election Day.

But in Wisconsin and Pennsylvania, election officials can’t begin the arduous process until polls open on Nov. 3.

In a new poll released Wednesday by Quinnipiac University, 63% of likely voters surveyed said they did not believe the country would know who the winning presidential candidate is on election night. Just 30% thought there would be a winner declared on Nov. 3.

Regardless, the new changes could almost certainly play a role in who wins both states.