Democrats Brad Schneider of Illinois, Carol Shea Porter of New Hampshire, and Pete Gallego of Texas lost re-election bids in 2014 in a tough environment. All are running again this year, likely to be a friendlier one for Democrats. The three races are rated "Tossup" by the Rothenberg & Gonzales Political Report/Roll Call.

But a handful of other former members who you might not even know are running face longer odds.

Joe Baca, Calif. 31: The California Democrat lost re-election in 2012 to fellow Democrat Gloria Negrete McLeod in the 35th District and failed in his 2014 comeback attempt in the 31st District, when he finished fifth out of seven candidates with 11 percent. This year, he's running as a Republican in the 31st District and will struggle to finish in the top two in the June 7 open primary.

Ric Keller, Fla. 6: The Florida Republican lost re-election in 2008 to Democrat Alan Grayson in an Orlando-based district after four terms in Congress. Keller just announced a run in the 6th District, which he has not represented before and where incumbent GOP Rep. Ron DeSantis is leaving to run for the Senate. Keller faces a crowded and competitive Republican primary on Aug. 30.

Baron Hill, Ind. Senate: The Indiana Democrat lost re-election in 2010 to Republican Todd Young in the 9th District which he represented for five non-consecutive terms. Hill is the Democratic nominee for Senate this year and faces Young in the general election where he remains a significant underdog.

Paul Broun, Ga. 9: The Georgia Republican left his 10th District seat in order to run for the Senate in 2014, where he finished fifth in the primary with 10 percent of the vote. Now he's challenging Rep. Doug Collins in the GOP primary in the 9th District. Broun's former chief of staff was indicted in April for allegedly misusing taxpayer money to finance campaign activities.

Joe Garcia, Fla. 26: The Florida Democrat lost re-election to Republican Carlos Curbelo in 2014, 51-49 percent. Garcia is running again in his old district, which was made significantly bluer after Florida's congressional maps were redrawn. But national Democrats prefer businesswoman Annette Taddeo to take on Curbelo. The Democratic primary is Aug. 30.