HARRISBURG, Pa. — California billionaire Tom Steyer is the first Democratic presidential candidate to file signatures to get on Pennsylvania’s primary ballot, according to information from the state election office Friday.

The other campaigns have through 5 p.m. on Tuesday to file 2,000 signatures of voters who are registered Democrats to get on Pennsylvania's April 28 primary ballot.

Pennsylvania is a late primary state, but nonetheless could be important if the eventual nominee remains in doubt past March since Pennsylvania has the sixth-most delegates in the Democratic primary.

Pennsylvania is seen as friendly territory for former Vice President Joe Biden, who has his campaign headquarters in Philadelphia and long political relationships in Pennsylvania after living for decades just across the border in Wilmington, Delaware, as that state's longtime senator.

However, Vermont Sen. Bernie Sanders made several visits to Pennsylvania last year and built a volunteer network in his first campaign in 2016.

Meanwhile, former New York Mayor Michael Bloomberg is spending millions of dollars on TV ads and campaign staff in Pennsylvania, and is known for funding antigun violence groups in the state and successful advocacy efforts for a soda tax in Philadelphia.

The Steyer-funded NextGen America political action committee is active in Pennsylvania, committing millions of dollars to register younger voters.