Several U.S. presidents have changed political party affiliations. Most notably, Ronald Reagan and Donald Trump transitioned from Democrat to Republican, while John Quincy Adams and Theodore Roosevelt changed parties multiple times throughout their long political careers. The National Constitution Center +4Details of these political migrations vary:Ronald Reagan: Began his political career as a staunch New Deal Democrat and served as the president of the Screen Actors Guild. He officially switched his affiliation to the Republican Party in 1962. Quora +1Donald Trump: Registered as a Democrat for much of the 2000s before shifting to independent, and eventually to the Republican Party, running successfully as a Republican in 2016. Theodore Roosevelt: Served his presidency as a Republican, but left the GOP in 1912 after failing to secure the presidential nomination, founding the Progressive Party (often called the "Bull Moose" Party). John Quincy Adams: Evolved through several shifting coalitions during the 19th century, transitioning from the Democratic-Republican Party to the National Republicans, the Anti-Masonic Party, and ultimately joining the Whig Party. QuoraJohn Tyler: Switched from the Jacksonian Democrats to the newly formed Whig Party. He was elected Vice President as a Whig, but during his presidency, he was ejected by the Whig party for vetoing their legislation. Beloud