"He wasn't perfect, but Roger Ailes was my friend & I loved him," the 41st president tweeted Thursday. "Not sure I would have been President w/o his great talent, loyal help. RIP."
Prior to launching Fox News in 1996, Ailes was a longtime Republican media consultant who also helped Presidents Richard Nixon and Ronald Reagan. For Bush, he helped craft
the infamous "Willie Horton" ad that accused Democratic nominee and then-Massachusetts Gov. Michael Dukakis of being soft on crime.
Ailes left Fox News last year after a series of sexual harassment allegations were levied against him. Ailes vehemently denied them.
Other GOP lawmakers praised Ailes for his transformative impact on news and politics and providing a platform for conservatives.
New York Rep. Peter King said he had "some differences" with Ailes but that doesn't diminish his impact on news and politics.
"He was a giant. He really revolutionized television and television news and the world of politics. And may he rest in peace," the lawmaker told CNN's Chris Cuomo Thursday on "New Day."
And former Arkansas Gov. Mike Huckabee went to work for Fox News after his first failed presidential run and eventually hosted a show on the network.
"Deeply saddened by death of Roger Ailes. He had many critics and like ALL of us his sins, but I remember a great patriot, friend and boss," he tweeted.
Fox News has hired numerous Republican lawmakers, including former Arkansas Gov. Mike Huckabee and John Kasich (before he became Ohio's governor), as well as those whose political careers were behind them, such as former Alaska Gov. Sarah Palin and former House Speaker Newt Gingrich.
"In the years I worked with Ailes he was a great mentor, deeply patriotic, committed to Fox News and really worried about America," Gingrich tweeted Thursday afternoon.
The network also served as a launching pad for some hoping to enter politics, particularly current Housing and Urban Development Secretary Ben Carson, who joined the network as a contributor in 2013.