Voters in Pennsylvania head to the polls for a more tumultuous than usual primary election.

The voting comes after court rulings that reworked election districts that heavily favored Republican candidates in the past.  Three Republicans are challenging Democrat Governor Tom Wolf while the race for the Lieutenant Governor post has five Democrats and four Republicans running.

Most closely watched will be races in the U.S. Senate and House that could affect the balance of power in Washington.

A number of Republicans facing primary contests in their states have opted not to run.

(Polls are open from 7 a.m. to 8 p.m. May 15.)