Republicans are pouring hundreds of thousands of dollars into a special election in Arizona, hoping to avoid another Democratic upset.
While the party has expressed confidence it can successfully defend its congressional seat in the historically Republican area, national Republican groups have recently committed more than a half-million dollars into the race, The Hill reported.
Donald Trump won the seat outside of Phoenix by 21 points during the last presidential election. But a recent Republican loss in another district that Mr Trump dominated in 2016 appears to have the party worried.
Normally, Republicans wouldnt have to spend very much to defend Arizonas 8th congressional district seat. Republicans make up about 41 per cent of registered voters in the district a 17-point advantage over Democrats.
It is also home to the expansive Sun City retirement community, providing Republicans with a loyal group of conservative voters.
Former state Republican senator Debbie Lesko is running against Democrat Hiral Tipirneni, a physician and first-time candidate. They are competing to fill the seat left vacant by former Republican Representative Trent Franks, who resigned from Congress last December after allegedly discussing paying a staffer to carry his child.
Mr Franks acknowledged discussing surrogacy with his staffers and apologised for making them feel uncomfortable. But he denied allegations that he made advances toward female staffers, saying he absolutely never physically intimidated, coerced, or had, or attempted to have, any sexual contact with any member of my congressional staff.
A scandal had also triggered an election in Pennsylvanias 18th congressional district.
In that race earlier this month, Democrat Conor Lamb beat his Republican opponent Rick Saccone by a fraction of a percentage point to claim a seat in the US House of Representatives.
Mr Saccones loss in a district that Mr Trump won in 2016 by double-digits has been seen as an ominous sign for the Republican Party ahead of Novembers midterm elections.
National Republicans are suffering from political PTSD over the Pennsylvania loss, Brett Mecum, an Arizona GOP strategist, told The Hill. I think they are overcompensating of getting involved in [the 8th District] to ensure victory.
A poll conducted for Ms Tipirnenis campaign in Arizona shows the Democrat trailing by 14 points, the newspaper said.