Former Rep. Quico Canseco (R-Texas) has been forced into a runoff in his primary, a result that could boost Rep. Pete GallegoPete Pena GallegoTexas Democrats smell blood in the water for 2018 ObamaCare repeal vote: 15 GOP lawmakers to watch Vulnerable Texas GOP lawmaker survives rematch MORE's (D-Texas) reelection chances.

Canseco leads former CIA agent Will HurdWilliam Ballard HurdProgressive group targets GOP moderates on immigration Obama failed on Russia; Trump must get it right House Dems rebuff Trump’s four-tier DACA approach MORE by 41 percent to 40 percent, below the 50 percent needed to win the primary outright. The two will now face off in a runoff election in late May, which will further sap their already-depleted campaign accounts.

The freshman Gallego holds the only swing district in Texas, a heavily Hispanic one rooted in San Antonio. Mitt Romney won it by three percentage points in 2012, while Gallego defeated Canseco by 5 percentage points.

Republicans have been hopeful about their chances against Gallego in an off-year election where Hispanic turnout drops, making him more vulnerable.

But Hurd and Canseco will struggle to catch up in fundraising. Both had less than $200,000 left in the bank as of mid-February and will have to keep spending ahead of the runoff race. Gallego had more than a half-million dollars in the bank as of last month.

Some Republican strategists also believe they need a Hispanic candidate to compete in the district, making the former one-term lawmaker's showing more disappointing.