By MARK SCOLFORODemocrats hoping to claw their way out of a deep minority in the Pennsylvania House of Representatives got some good news this week when their candidates filed petitions to get on the ballot in 180 of the chamber's 203 districts. The flood-the-zone strategy, inspired in part by a surprising showing for their party in Virginia in November, is designed to put more of the chamber in play and ramp up pressure on Republicans to defend their 121-82 majority. Some of those candidates can expect legal challenges to their petitions or their qualifications, but their sheer numbers suggest that Democrats are benefiting from energy and enthusiasm that could change the Legislature's balance of power. “Obviously, 2016 was not exactly what we were hoping for and we had a very intentional strategy to challenge Republicans in every district," said Nathan Davidson, director of the House Democratic Campaign Committee. “We didn't quite get there, but it was very intentional to be actively recruiting in every place." The 180 districts would be the most for Democrats since at least 2000. That beat 2006, when Democrats ran in 175 districts. That year, Democrats rode a national wave to control of Congress, while at home, a populist furor over lawmakers' self-granted pay raise fueled the defeat of 24 incumbents and briefly put Democrats in the majority. Allegheny County Rep. Mark Mustio, who leads House Republican campaign efforts, said numbers alone don't mean much. “There are some of their candidates that have significant problems — we know that," Mustio said. “Some of them, we hope, will stay on the ballot because they're unelectable." The House Republicans' electoral challenges this year are compounded by their 20 retirements and other vacancies, compared to seven for Democrats. Any seat without an incumbent becomes more attractive to the other side. There are 51 House Democrats with no Republican opposition at all this year, compared to 22 Republicans without a Democrat taking them on. The filings mean that 78 Republican incumbents are in line to get Democratic challengers in the fall, including all GOP representatives in the four suburban counties around Philadelphia, in the Lehigh Valley and in the Pocono Mountains. All are battleground areas in the politically divided state. That's more than three times the 24 sitting Democratic lawmakers who have the prospect of a Republican opponent in November. Primary write-in campaigns, legal challenges or dropouts could change those numbers. The dynamic is similar in the state Senate, where 18 of the 25 seats up this year are held by Republicans. Both parties have candidates in the four open seats, all currently represented by Republicans. There are 13 Republicans and two Democrats who are in line to face opposite-party challengers in the fall. The Senate is currently in Republican hands, 34-16. The state House strategy positions Democrats to take advantage if this turns out to be a wave election year. Davidson said his side is reaping a crop of new volunteers. “More than 50 percent have been new people who have come out of the woodwork and said, `The world is changing and I need to do something,"' he said. Seeking re-election this year is Democratic state Rep. Tom Caltagirone, whose former aide's claim of sexual harassment was settled with a $250,000 payment from taxpayer funds. Republican Rep. Nick Miccarelli, the subject of a sexual misconduct complaint by two ex-girlfriends, also filed for another term, as did Democratic Rep. Vanessa Lowery Brown, awaiting trial on public corruption charges that include an allegation of accepting bribes from an informant. A constitutional amendment to shrink the number of state legislators will not be on the primary ballot, but could still go before voters in November.