As S.C. governor, his rigid ideological conservatism made him a favorite of tea party Republicans while putting him at odds with state lawmakers over spending.
Trump, saddled with low approval ratings, has emerged as a focal point in several races around the country. He went on to attack Trump's penchant for lying and distorting facts.
"We're in a odd place".
He also thrusted blame onto Trump for increasing divides within the modern Republican party and creating an even more volatile political climate.
He becomes the second incumbent House Republican to lose a primary this year - the latest victim of intense divisions among the GOP in the Trump era.
Sanford found out just how tight the grip is.
President Donald Trump tweeted out his picks in two primary races Tuesday, hours before the first polls closed in the night's five states holding elections.
The Richland Republican finished first with a strong showing in Tuesday's primary but fell short of the 50-percent-plus one majority needed to clinch the GOP nomination outright.
Incumbency, period: Being an early backer of Trump doesn't always help save Republicans from primary challenges. In a February 2017 Politico piece, he said Trump has "fanned the flames of intolerance".
Moments after arriving back in the USA from Singapore on Wednesday morning, Trump tweeted his congratulations.
Former Rep. Reid Ribble (R-Wisc.) expressed outrage at Sanford's loss, noting that the SC congressman "supported POTUS with his votes" from taxes to healthcare to spending. Sens. Jeff Flake (R-AZ) and Bob Corker (R-TN) are also heading for the exits largely because GOP base voters abandoned them after their attacks on the president, and Rep. Martha Roby (R-AL) was just forced into a primary runoff last week because she refused to back Trump in 2016. He will not appear on Tuesday's primary ballot since he is the only Republican candidate running for the position. The eventual victor will challenge Republican Rep. Bruce Poliquin.
Sanford, who was elected to the House of Representatives in 2013, was most recently polling at a statistical tie with his challenger, state Rep. Katie Arrington. Kaine is the heavy favorite in November. In the years after Ron Paul's 2008 dark horse presidential run, he and then-governor of New Mexico Gary Johnson (along with, of course, Rand Paul) were often identified as the heirs apparent to the libertarian wing of the GOP.
Besides that district, considered key to the House battleground map this fall, Democrats in two other Virginia districts they hope to retake nominated women, including Abigail Spanberger in the 7th District and Elaine Luria in Virginia's 2nd District. "Don't underestimate Corey, a major chance of winning!". For the most part, Trump has stayed in the background.