(CNN) – Former President Bill Clinton sent good wishes Wednesday to his adoptive Republican mother and former first lady Barbara Bush, who's been hospitalized in Houston since Monday.
"I'll be rooting for Barbara Bush's full recovery while she's rooting for Baylor today. All my best to her and @GeorgeHWBush," he tweeted.
Baylor, located in Waco, Texas, plays against the University of Central Florida in the Fiesta Bowl Wednesday night.
Despite defeating former President George H.W. Bush in 1992, Clinton has become close with the Bushes over the past decade, as the 41st and 42nd presidents have teamed up to work on humanitarian issues.
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Clinton joked about becoming part of their family last April.
"Starting with my work with President George H.W. Bush on the aftermath of Katrina, people began to joke that I was getting so close to the Bush family, that I had become the black sheep son. My mother told me not to talk too long today, and Barbara, I will not let you down," Clinton said at the dedication ceremony for George W. Bush's presidential library in Dallas.
In a 2012 interview with Parade Magazine, Barbara Bush said her sons call Clinton their "brother by another mother."
"He's very nice-I think he thinks of George as the father he never had," she added. "Truthfully. I mean that as a great compliment. He's been very thoughtful about calling and he's a good fellow."
The outspoken former first lady said she was "surprised by the fact that I liked him, truthfully."
"And I do like him a lot," she continued. "And he and George W. have worked together. I think they're patriots."
A family spokesperson said Wednesday Bush, 88, is getting treatment for a "respiratory-related issue" and her condition remains unchanged.