Conservative commentator Sean Hannity has endorsed Virginia Del. Barbara ComstockBarbara Jean ComstockTax law supporters rally for Republicans in tough races Congress — when considering women’s health, don’t forget about lung cancer GOP split on immigration is a crisis for Ryan’s team MORE's (R) House bid, the latest big-name boost to her campaign.

"Barbara Comstock is a solid and reliable conservative. I've known her for many years. She'd make a great member of Congress. I am happy to join other conservatives and proudly endorse her candidacy," Hannity said.

The radio and TV host is the latest influential Republican to endorse Comstock, who is facing off against three other Republicans for the nomination to succeed retiring Rep. Frank Wolf (R-Va.).

Comstock also has the backing of former GOP presidential nominee Mitt Romney, conservative radio host Mark Levin and the conservative group Citizens United.

She had a 30-point lead over her primary rivals in a poll from Citizens United released earlier this week; she's posted big fundraising numbers since she got into the race.

Democrats are hoping to compete for the GOP-leaning northern Virginia seat this fall.