The ballot count is expected to draw intense scrutiny amid heightened concerns over election integrity.
“We may not know all the winners of elections for a few days,” White House press secretary Karine Jean-Pierre told reporters on the eve of Election Day.
Ballot counts, automatic recounts, and challenges to the results could all slow the final results for Tuesday’s races and could stoke concerns about the legitimacy of some close races.
The results will determine control of the House and Senate heading into 2024, complicating President Joe Biden’s next two years in office if Democrats lose control.
The comments by Biden’s press secretary come as polls show late ballots breaking toward Republicans.