President Donald Trump on Tuesday celebrated primary results, calling it a “big night” as his favored Republican candidates carried the day, while a socialist dethroned a heavyweight Democrat.

“The Democrats are in Turmoil!” Trump wrote on Twitter. “Open Borders and unchecked Crime a certain way to lose elections. Republicans are for Strong Borders, NO Crime! A BIG NIGHT!”

Former Massachusetts Gov. Mitt Romney won the primary runoff in the race to take the place of retiring Utah Republican Sen. Orrin Hatch.

He beat state Rep. Mike Kennedy, who put up a fight during the first round of the primary, blocking Romney’s attempt to secure to the majority of the vote. Romney will now face Democrat Jenny Wilson, a city councilwoman.

Trump, who had on-and-off relationship with Romney since the beginning his presidential campaign bid, celebrated Romney’s victory, tweeting: “Big and conclusive win by Mitt Romney. Congratulations! I look forward to working together - there is so much good to do. A great and loving family will be coming to D.C.”

In South Carolina, Gov. Henry McMaster was projected the winner of Tuesday’s Republican gubernatorial runoff election. Trump was heavily invested in the race, offering full support and even campaigning on McMaster’s behalf in recent days.

Rep. Dan Donovan of New York, another Trump-backed candidate, also cruised to primary victory, defeating Michael Grimm, whose candidacy was seen as controversial over his conviction for tax fraud.

On the Democrats’ side, Rep. Joe Crowley, D-N.Y., was dethroned after suffering a shock defeat against 28-year-old political newcomer Alexandria Ocasio-Cortez.

Crowley, a 10-term Democratic lawmaker, whose name was floated as a potential future Speaker of the House, was bested by Ocasio-Cortez, who campaigned on the platform of abolishing U.S. Immigration and Customs Enforcement (ICE), universal health care and assaults weapons.

Left-wing groups also celebrated the political newcomer’s shock win, seeing it as a slap in the face to the establishment that isn’t progressive enough.

Soon after the race was called, the New York City branch of the Democratic Socialists of America issued a tweet saying her victory showed “that working class people are hungry for a voice in politics."

In a statement, Crowley congratulated Ocasio-Cortez on her victory and said he looked forward to supporting her against Republican Anthony Pappas in November.

"The Trump administration is a threat to everything we stand for here in Queens and the Bronx, and if we don't win back the House this November, we will lose the nation we love," Crowley said. "This is why we must come together. We will only be able to stop Donald Trump and the Republican Congress by working together, as a united Democratic Party."

Fox News’ Gregg Re, Samuel Chamberlain, and the Associated Press contributed to this report.