Former president George W. Bush is back. He will appear in an ad designed for brother Jeb! Bush's Super PAC, Right to Rise.

"The first job of the president is to protect America. The next president must be prepared to lead. I know Jeb. I know his good heart and his strong backbone," Bush says in the 30-second Right to Rise spot, which spotlights the former president speaking directly to the camera.

"Jeb will unite our country. He knows how to bring the world together against terror. He knows when tough measures must be taken,” Bush adds. “Experience and judgment count in the Oval Office. Jeb Bush is a leader who will keep our country safe."

The ad is set to air in South Carolina on Friday, according to sources at Politico.

The launch of the ad comes at a crucial moment for Jeb Bush, who fared poorly in Iowa and is coming under growing pressure to demonstrate strength in the Republican primary. In recent days, establishment donors, lobbyists, and lawmakers have expressed growing concern about the state of Bush’s campaign and are beginning to gravitate to one of his chief rivals, Marco Rubio.

A spokesman for George W. Bush, Freddy Ford said about the ad, “I think it speaks for itself. He's said from day one that Jeb is the best candidate and will be a great President.”