Former senator Rick Santorum announcing in Cabot, Pa., that he will seek the Republican presidential nomination. (Andrew Harrer/Bloomberg News)

Rick Santorum, who announced this week that he will run for the 2016 Republican nomination for president, said he was “sickened” upon learning of the molestation allegations against Josh Duggar.

Duggar and his family supported Santorum’s 2012 bid for the nomination. In an interview Thursday on ABC’s “Good Morning America,” George Stephanopoulos asked the former U.S. senator for his reaction to the revelation last week that the oldest Duggar son had molested several young girls while he was a teenager.

“I was sickened by it. I was just sickened by it,” Santorum said.

“I pray for those girls in particular,” he said of Duggar’s alleged victims. “To have gone through that is just hard to think about.”

[A timeline of the molestation allegations against Josh Duggar]

Duggar, now 27, apologized for unspecified “wrongdoing” in a statement, after In Touch Weekly first published a lengthy police report containing the allegations against him. Although he did not specifically address the allegations in his statement, Duggar said he “acted inexcusably for which I am extremely sorry and deeply regret.”

He also resigned from his job at the Family Research Council, a conservative lobbying organization.

Duggar stars with his family in the popular TLC reality show “19 Kids and Counting,” which wrapped up its most recent season on May 19.  The cable channel pulled all of the show’s re-runs from its schedule on Friday, in light of the “heartbreaking situation.” TLC had no comment Thursday on the channel’s long-term plans for the show.

But several companies — including General Mills and Walgreens — have said that they’re no longer interested in advertising their products during the program, should it return to air.

Santorum’s brief remarks were markedly different from those of another presidential hopeful who also has leaned on the Duggar family for support.

[How do evangelicals view the Duggars? It’s complicated.]

A day after the allegations surfaced, Mike Huckabee slammed the media for “sensationalizing” the Duggar story. “Josh’s actions when he was an underage teen are as he described them himself, ‘inexcusable,’ but that doesn’t mean ‘unforgivable,'” Huckabee said in a written statement.

“No one needs to defend Josh’s actions as a teenager, but the fact that he confessed his sins to those he harmed, sought help, and has gone forward to live a responsible and circumspect life as an adult is testament to his family’s authenticity and humility.”

Earlier this year, the Duggar family endorsed Huckabee’s 2016 run for the Republican nomination, as the family did in 2008.

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Republicans’ Josh Duggar problem