Four states have primary elections on Tuesday, and although voter turnout is typically lower in midterm elections — especially primaries — experts say they expect a different story in Pennsylvania.
"It's almost like Christmas. Everyone likes the new toy, so everyone wants to play with it," said Micah Sims, executive director of the Pennsylvania chapter of Common Cause, a nonpartisan government reform watchdog.
That "new toy" is a new congressional map.
In January, the Pennsylvania Supreme Court ruled that the previous congressional map was gerrymandered to favor Republicans. The court ended up drawing new district lines after the state's GOP-controlled legislature and Democratic governor couldn't agree on a new map.
The result? A map that could dramatically change the state's congressional delegation and possibly the balance of power in the U.S. House.
"The Democrats have a possibility of picking up four to possibly five seats that, when you add that in to the overall narrative that's happening in the country, could actually mean that Pennsylvania could actually be the place where Congress gets tilted to Democratic leadership," Sims explained.
President Donald Trump narrowly won the state in 2016, and its congressional delegation is mostly Republican now, so the change has generated a lot of national interest.
U.S. Sen. Bernie Sanders has been stumping in Pennsylvania for candidates before the state's May 15 primary elections, and super PACs, like Tom Steyer's NextGen America, have spent millions of dollars on political ad campaigns in the state.
Democrats need to flip 23 seats to take control of the House. They won't get all of them in Pennsylvania, but they have a chance to win quite a few, and plenty of candidates could help them succeed.
Nearly 100 people, mostly Democrats, launched congressional bids in the state, and many are running for the first time.
"I think that speaks to the level of interest that people have and the way that these new maps are really causing what we would call responsiveness. People are responding well to the fact that these maps are catered to more communities of interest — they are more compact, they are more continuous, and that's going to help people feel like their voices are going to be heard on election day," Sims said.
All of that excitement around the new map could make May 15 a very competitive day for candidates in Pennsylvania and a very long night for politicos watching the results.