They're popping up like mushrooms — Democratic candidates for Congress that is, a crop apparently fertilized by the election of Donald Trump.

Though congressional elections won't happen until 2018, several Democrats have already announced they want to challenge Republican representatives in the Philadelphia suburbs next year.

It's by no means just a Philadelphia phenomenon.

"Our office has received more unsolicited calls from potential candidates than we ever have in the past," said Ken Snyder, a Chicago-based consultant who works on races here and around the country.

"Everywhere you look, there are Democratic primaries happening in districts where Republicans have traditionally won by 20 points," Snyder said. "I've been talking to candidates in central Texas where there's an incumbent who hasn't been challenged significantly since the '90s."

Democratic strategist Mark Nevins said the burst of political activism spurred by the Trump election is real.

"There's a feeling among Democrats that perhaps they did not play as hard as they needed to in 2016, and now they're seeing the result," Nevins said. "They're not going to let that happen again. So there's a lot of energy and a lot of passion — and a lot of new candidates running for office."

A number of potential candidates have emerged to challenge two Republican congressmen in the in the Philadelphia suburbs.

Former congressional staffer and former Cease Fire PA head Dan Muroff is challenging U.S. Rep. Pat Meehan in the 7th Congressional District, along with biomedical researcher Molly Sheehan and tech consultant Drew McGinty.

Also considering a run in the 7th is veteran Montgomery County state Sen. Daylin Leach.

In the 6th Congressional District, Chrissy Houlahan is up and running against two-term incumbent Ryan Costello. Houlahan was most recently chief operating and financial officer for Springboard Collaborative, a nonprofit that seeks to boost literacy among low-income kids.

Democrat Bob Dettorre of Berwyn is also in the race, and the field may grow.

Both Snyder and Nevins said 2018 could be a great year for Democrats if progressives turnout in big numbers and independent voters sour on Trump.

Republicans, of course, have other plans — and both Meehan and Costello will be formidable candidates.

Republican runners, too

We've also seen a burst of Republican candidates emerging for next year's races for governor and U.S. Senate.

Democratic Gov. Tom Wolf has struggled with a big budget deficit, and the GOP loves to cite a 2015 Huffington Post survey that called him the most liberal governor in the country.

Already in the race are state Sen. Scott Wagner, R-York, who has money and determination, and retired Pittsburgh businessman Paul Mango.

In addition, State House Speaker Mike Turzai seems to be assembling a campaign team, though he hasn't yet declared he will run.

Republican strategist Charlie Gerow said candidates aren't waiting for next year.

"These campaigns are now in earnest. They're out on the track and running hard. It's not even like they're warming up," Gerow said. "They're obviously talking to a much smaller audience than they will be later on. But they're lining up support among key people and key constituencies right now."

A GOP crowd is also forming to take on Democratic U.S. Sen. Bob Casey.

Rick Saccone, a conservative state representative has announced for that race, along with state Rep. Jim Christiana. Both are from Southwestern Pennsylvania.

Lower Merion real estate executive Jeff Bartos has announced his candidacy, and some other heavyweights are said to be weighing a run, including U.S. Reps. Mike Kelly and Lou Barletta.