Jonathan Lai for Philly Inquirer:

A heated court fight over Pennsylvania mail ballots will determine who wins the election. And the decision could well ripple beyond 2020.

The fight isn’t over the presidency, of course — Joe Biden is clearly the president-elect — but a state Senate seat in Western Pennsylvania that hinges on just a few dozen votes.

At its narrowest, Ziccarelli v. Allegheny County Board of Elections is an argument over 2,349 mail ballots cast in Allegheny County that arrived in time but lacked dates filled out on the envelopes. Those ballots, including 311 votes in the 45th Senatorial District, gave incumbent Sen. Jim Brewster, a Democrat, the win by just 69 votes. The state Supreme Court affirmed Allegheny County’s decision to count the votes.

But the district crosses into Westmoreland County, one of the counties that decided not to count ballots that lacked dates, classifying them as incomplete. That creates an unfair situation, Republican challenger Nicole Ziccarelli argued in her federal court lawsuit. Similar votes are being handled differently in different counties, which she says violates the U.S. Constitution’s equal protection guarantees.