HARRISBURG — Lots of people want to run for Congress in Pennsylvania this year, but they may not yet know which district they live in.

The prospect that the state Supreme Court could decide a high-profile gerrymandering case by ordering new boundaries for Pennsylvania’s 18 congressional districts, including one that has been described as looking like “Goofy kicking Donald Duck,” is sowing uncertainty barely a month before candidates begin circulating petitions.

Primary fields could be jam-packed, driven by Democrats’ anti-Trump fervor and a rush to fill the most open seats in Pennsylvania in decades.

More than 60 people, including 14 sitting U.S. House members, are either committed to running or are kicking the tires on a run, even as district boundaries could get a major overhaul.

“It’s on everybody’s mind, because it leaves big questions of how’s this going to work out,” said Elizabeth Moro, a Democrat and first-time candidate from southeastern Pennsylvania who wants to challenge Republican U.S. Rep. Pat Meehan.

For comparison, there were 41 U.S. House candidates, including 16 incumbents, on Pennsylvania’s primary ballots in 2016.

On Wednesday, the state Supreme Court — which has a 5-2 Democratic majority — will hear arguments in the 7-month-old case urging the court to throw out Pennsylvania’s congressional districts as an unconstitutional gerrymander that unfairly favors Republicans.

To be sure, Republicans who controlled the Legislature and governor’s office following the 2010 census broke decades of geographical precedent when redrawing the map.

They shifted whole counties and cities into different districts and produced contorted boundaries in an effort to protect a Republican advantage in the congressional delegation. They succeeded, securing 13 of 18 seats in a state where registered Democratic voters outnumber Republicans 5 to 4.

In Republican U.S. Rep. Lou Barletta’s 11th District in northeastern Pennsylvania, Republicans cut out Scranton and Wilkes-Barre and sent the district plunging more than 75 miles into south-central Pennsylvania.

Now, Steve Bloom, a Republican state representative from the Carlisle area, is campaigning to succeed Barletta, who is running instead for U.S. Senate. Bloom faces the possibility that, in a few weeks, he may no longer live in the district, even as he campaigns 100 miles from his home.

“All I can do is keep my head down and keep working hard,” Bloom said.

On Feb. 13, candidates can start circulating petitions to get on the primary ballot. The paperwork is due March 6 and the primary election is May 15.

In court filings, the plaintiffs — a group of Democratic voters — asked the state Supreme Court to redraw district boundaries if the Legislature and governor cannot do it within a two-week window.

The defendants — Senate President Pro Tempore Joe Scarnati, R-Jefferson, and House Speaker Mike Turzai, R-Allegheny — argue that the justices shouldn’t create a standard to determine when partisan bias in mapmaking goes too far, particularly when the U.S. Supreme Court could soon resolve similar cases from other states.

In any case, the defense team would “pursue all possible avenues” to appeal an adverse ruling to the U.S. Supreme Court, a defense lawyer, Robert Tucker, said.

In last month’s fact-finding trial, a top state elections official testified that the primary election can still be held May 15 if a new map is in place before Feb. 21. The period to circulate petitions could be postponed and compressed to March 6-20, the official, Jonathan Marks, testified.

As an alternative, a primary could be held as late as July 31 to provide until early April to install a new map, Marks said.

Democrats figure that Pennsylvania’s map can’t get any worse, and seem willing to live with any inconvenience from a court-ordered redrawing. Candidates aren’t required to live in the district, but the resulting accusations of carpetbagging can be a political liability.