"My opponent, for whatever reason, makes statements that have no bearing in truth and can't be backed up," Issa said. "If we say something, we'll tell you what it is attributed to, where we got our facts, because facts matter."
DeMaio, who has been targeted by anti-gay attacks in past campaigns, did not comment on whether he finds this ad offensive.
"I'd much rather talk about things that matter to voters -- like how Darrell Issa authored the amnesty law to benefit 11 million illegal immigrants, or was the only Republican to call for a special prosecutor to investigate President Trump," DeMaio said in an email.
Issa's ad drew criticism from prominent local Republicans, some of whom are firmly in Issa's camp.
San Diego Mayor Kevin Faulconer, a Republican who this week endorsed Issa, did not appear to withdraw his endorsement over the ad.
"I can confirm that the mayor has endorsed Darrell Issa and also confirm that Mayor Faulconer is a longstanding ally of the LGBTQ community," said Faulconer's spokesman Matt Awbrey in an email.
"Campaigns should focus on people's positions on the issues, not people's sexual orientation."
Republican San Diego City Councilman Chris Cate criticized the ad on Twitter. Chairman of the Republican Party of San Diego County Tony Krvaric said the ad crossed the line.
"Highly inappropriate," Krvaric said. "We encourage all candidates to stick to the issues."
The ad also drew criticism from many Democrats, including some who have been targets of DeMaio in the past.
"There are a lot of reasons not to vote for Carl but his sexual orientation isn't one of them," tweeted Assemblyman Todd Gloria, who is running for mayor. "Darrell Issa should be ashamed of engaging in such bigotry."
Issa and DeMaio will square off at a 50th District Congressional Forum on Feb. 7, in Valley Center, where they'll be joined by fellow candidates Democrat Ammar Campa-Najjar and Republican state Sen. Brian Jones.
The 50th District includes swaths of East County, inland North County and a small portion of Riverside County. The district's congressional seat is empty after former Rep. Duncan D. Hunter, R-Calif., resigned this month after pleading guilty to a federal felony charge.
(c)2020 The San Diego Union-Tribune
Visit The San Diego Union-Tribune at www.sandiegouniontribune.com
Distributed by Tribune Content Agency, LLC.