Both parties have been trying for months to recruit challengers in the districts — Bucks County’s 8th, Berks County’s 6th and Carbon and Monroe counties’ 11th. The next couple of weeks will provide a clearer picture of who’s in and who’s out.

In Bucks, Republicans have their eye on Thomas Manion, a 53-year-old pharmaceutical executive whose son, Travis, was killed in a sniper attack in April near Fallujah. The matchup would pit a strong supporter of the war — in Manion — against one of Congress’s most high-profile advocates of a troop withdrawal — in Murphy, the only House lawmaker to have served in Iraq.

Manion’s entry into the race would almost certainly mean that former Rep. Mike Fitzpatrick, who lost to Murphy in a tight contest in 2006, won’t seek the seat again this year. Fitzpatrick has said since he left office that he is considering another run, but he has been talking up Manion as a potential candidate and is helping him lay the groundwork for a campaign. He introduced him to national Republican Party leaders last year.