1. President Bill Clinton: Phi Beta Sigma (and many others)
Bill is actually a part of many fraternities -- Phi Beta Sigma, a traditionally all-black fraternity, inducted him as an honorary member. But he was also part of Phi Alpha Delta, a legal fraternity, during his years at Yale Law -- where, fun fact, he actually met Hillary. In his undergrad years at Georgetown, he was an Alpha Phi Omega -- now, it's a co-ed service fraternity, but while he was in college it was all-male.
2. Speaker of the House, Paul Ryan: Miami University of Ohio, Delta Tau Delta
Paul Ryan was a Delta Tau in his college days. He's also the only one on this list that didn't go to an Ivy League school. And, he's also the youngest on this list. Look at that face. Mmm.
3. Presidents George W. Bush, Jr. & George H.W. Bush, Sr.: Yale University, Delta Kappa Epsilon
Ha, of course W. did the same thing as H.W. Duh. All jokes aside, of course, both of the Bush's are members of Delta Kappa Epsilon at Yale. H.W. Bush's vice president, Dan Quayle, attended the DePauw chapter of Delta Kappa Epsilon, and his wife, Barbara, was an alumna initiate of Pi Beta Phi at Texas A&M University.
4. Republican Presidential Candidate and Senator, John Kasich: Ohio State University, Alpha Sigma Phi
One of two on this list who attended a large public university, John Kasich was an Alpha Sig at Ohio State, studying political science. He actually met President Richard Nixon as a freshman at Ohio State. Besides that point, John Kasich really loves Ohio.
5. Former Governor of Florida and Republican Presidential Candidate, Jeb Bush: University of Texas at Austin, Phi Beta Kappa
Jeb! constantly makes an effort to deter himself from his brother's legacy--so, you would expect him to not go to Yale like his brother and father, and to attend his home state's fore-fronting university. However, Phi Beta Kappa isn't your typical frat--it's the largest honor society in the country. So, gold star for being smart, Jeb.
6. Republican Presidential Candidate Dr. Ben Carson: Yale University, Alpha Phi Alpha
Much like our knowledge of the "truth" of Ben Carson's life and his shady memoirs concerning Yale, no one is really sure if he was in the traditionally all-black Alpha Phi Alpha at Yale or if he was inducted to it post-graduation.
7. President John F. Kennedy: Harvard University, Phi Kappa Theta
While you probably already thought that JFK was a frat boy by (stereotypical) nature, he was actually inducted to Phi Kappa Theta as an honorary member. He did, however, attend Harvard, but without being recruited into a fraternity himself.
8. Republican Presidential Candidate and Businessman, Donald Trump: Fordham University, Phi Gamma Delta
Yes, the Donald was in a frat. You already knew that, though. Although he didn't complete his four years at Fordham--he transferred to the Wharton School of Business to finish his degree--, some websites said that he was a Phi Gam. Also take into account that Trump is pretty terrible at citing actual sources, so I could be totally wrong about this. Who knows.