HARRISBURG, Pa. (AP) — Democrat Joe Biden’s narrow but growing margin in the presidential race drew him closer to winning Pennsylvania’s cache of 20 electoral votes Friday as county-by-county teams of ballot counters continued to toil.

The canvassing that in a normal year would be wrapping up on Friday will carry into next week, with many counties waiting until Monday to begin going through provisional ballots.

Tens of thousands of remaining mail-in ballots — as well as the provisional ballots and those cast by military and overseas voters — will decide whether Biden’s slim lead holds up or if Republican President Donald Trump can find the votes he needs to repeat his 2016 victory in the state.

Starting to count provisional ballots on Monday, some counties decided, will help ensure that they can include all valid mail-in votes arriving by Friday that were sent on or before Election Day. Philadelphia officials said Friday that process may take several days.