Officials warn ballot counting process could delay Tuesday’s election results in key states

Election experts predict absentee ballot rules will slow the results in Pennsylvania. The state does not allow election workers to begin processing ballots until Election Day.

Polls show Pennsylvania is virtually a tie between Ms. Harris and Mr. Trump. A close result combined with expanded voting by mail means the delayed processing will almost guarantee a delayed result.

“It will likely take days to count all of the absentee ballots necessary to determine the winner in a state with such close margins,” Matt Germer and Chris McIsaac predicted for the R Street Institute, a policy research firm.

In 2020, Mr. Biden defeated Mr. Trump in Pennsylvania by about 1 percentage point. The Associated Press projected the state for Mr. Biden four days after the Nov. 3 election, but the counting wasn’t finished. The state did not certify the results until Nov. 24, and even then, two counties had not certified their results.

Secretary of the Commonwealth Al Schmidt told CBS News in October: “The message is, please be patient.”

Wisconsin

Like Pennsylvania, the state is prohibited from counting absentee ballots until Election Day, which could slow down the process of determining a winner. R Street reported that results may also be slowed in Milwaukee and dozens of other cities that require absentee ballots to be counted at a single location. Mr. Biden won Wisconsin by 0.63 percentage points in 2020.