The Democratic National Committee has turned to former Attorney General Seth Waxman for a new fight against Pennsylvania’s election law.

On Friday the Democratic National Committee attempted intervene in a Pennsylvania lawsuit filed by the Republican National Committee, which wants the state’s highest court to prohibit election officials from counting undated or incorrectly dated ballots. Waxman, a WilmerHale partner who was attorney general in the Clinton administration, and a group of lawyers from Dentons in Pittsburgh represent the Democratic National Committee.

The case is among several legal fights brewing in the final days of a contentious election season in which control of the White House and…