The Asso­ci­at­ed Press has not declared a win­ner in the bat­tle­ground state of Penn­syl­va­nia because there were hun­dreds of thou­sands of votes left to count Thurs­day in the con­test between Pres­i­dent Don­ald Trump and Demo­c­rat Joe Biden.

Penn­syl­va­nia is among a hand­ful of bat­tle­ground states Trump and Biden are nar­row­ly con­test­ing as they seek the 270 elec­toral votes need­ed to win the presidency.

Trump, who held a 675,000-vote lead ear­ly Wednes­day, pre­ma­ture­ly declared vic­to­ry in the state.

“We’re win­ning Penn­syl­va­nia by a tremen­dous amount. We’re up 690,000 votes in Penn­syl­va­nia. These aren’t even close. It’s not like, ‘Oh, it’s close,’” Trump said dur­ing an appear­ance at the White House.

But by Thurs­day after­noon his lead had slipped to about 90,000 votes, as mail in bal­lots from across the state con­tin­ued to be count­ed. The late count­ed bal­lots were over­whelm­ing in Biden’s favor.

One rea­son for the tight­en­ing race: Under state law, elec­tions offi­cials are not allowed to process mail-in bal­lots until Elec­tion Day. It’s a form of vot­ing that has skewed heav­i­ly in Biden’s favor after Trump spent months claim­ing — with­out proof — that vot­ing by mail would lead to wide­spread vot­er fraud.

There’s a pos­si­bil­i­ty the race won’t be decid­ed for days. If there is less than a half per­cent­age point dif­fer­ence between Biden and Trump’s vote total, state law dic­tates that a recount must be held.

Democ­rats had long con­sid­ered Penn­syl­va­nia a part of their “blue wall” — a tri­fec­ta that also includes Wis­con­sin and Michi­gan — that for years had served as a bul­wark in pres­i­den­tial elec­tions. In 2016, Trump won each by less than a per­cent­age point.

Biden, who was born in Scran­ton, claims favorite-son sta­tus in the state and has long played up the idea that he was Pennsylvania’s “third sen­a­tor” dur­ing his decades rep­re­sent­ing neigh­bor­ing Delaware. He’s also cam­paigned exten­sive­ly in the state from his home in Delaware.