Washington (CNN) If a progressive war against the Democratic establishment is coming, Tuesday's primaries were the first shots fired.

The soul searching within the Democratic Party that, to date, had played out largely on the sidelines was thrust into the spotlight on Tuesday in a series of primaries that amounted to arguably the best night for progressives this year.

Their biggest win: Democratic socialist Alexandria Ocasio-Cortez defeating Rep. Joe Crowley, a 10-term incumbent, in New York's 14th Congressional District primary, a stunner that rocked the Democratic world and shook up the party's line of succession.

But it wasn't their only victory.

Progressive candidates also won two gubernatorial primaries, with 2016 Bernie Sanders ally and former NAACP head Ben Jealous winning in Maryland and Rep. Jared Polis in Colorado.

Until now, there had been few signs of a mounting progressive insurgency. Kara Eastman had defeated former Rep. Brad Ashford in a Nebraska Democratic congressional primary, and Democratic socialists had won down-ballot races in Pennsylvania and elsewhere. But progressives declined to challenge the party's sitting senators and in the most important election of 2017 -- the Virginia governor's race -- Lt. Gov. Ralph Northam defeated his more liberal primary opponent, former Rep. Tom Perriello.

Now, though, Ocasio-Cortez's victory could embolden liberal challengers in both 2018 and 2020.

All of this played out at the same time that President Donald Trump demonstrated that the White House's bully pulpit, especially in Republican primaries, still carries considerable weight.

Trump, in a series of tweets and one rally, pushed two vulnerable Republicans across the finish line on Tuesday, landing wins for Gov. Henry McMaster in South Carolina and Rep. Dan Donovan in New York. The two vulnerable Republicans had come under considerable pressure from their own party and successfully leaned on Trump for help.

It wasn't all good news for Trump, however: Mitt Romney, a Trump foil and Republican heavyweight, moved one step closer to Washington -- and a powerful perch to pester the President.

Here are our five key takeaways from a shocking primary night:

A shocker in Queens

The out-of-nowhere upset of Crowley, the fourth-ranking Democrat in the House, in Tuesday's New York primary stunned the Democratic establishment, shook up the party's line of succession to become the next House speaker and might even be an early sign of a mounting progressive insurgency -- potentially with major ramifications in 2020.

Crowley was ousted from his Queens district by Democratic socialist Ocasio-Cortez, a 28-year-old Latina running her first political campaign. She is now likely to be the youngest woman ever elected to the House.

It was the most shocking result of 2018's political season so far, and could signal a restive base as the 2020 presidential primary approaches. Crowley is the only Democratic incumbent so far to lose his seat in a primary this year.

Ocasio-Cortez won despite being wildly outspent by Crowley, who leaned on his Democratic contacts to raise $3.3 million compared to her roughly $300,000.

Crowley quickly conceded and backed Ocasio-Cortez, who said in her victory speech that "what we proved tonight is that sometimes the deep midnight and darkness that it feels in our political environment, that there is still hope for this nation."

Donald Trump gets his men

The same night Democrats were delivered an earth-shattering blow, Trump's power as President was validated.

In two key races -- one for governor of South Carolina and another for a New York House seat -- the candidate Trump backed made it into the general election, riding the President's backing to victory with base Republicans voters.

Trump's intervention was needed for two incumbent Republicans -- Gov. Henry McMaster in South Carolina and Rep. Dan Donovan -- both of whom were fending off insurgent challenges.

But, in the end, McMaster outlasted Republican John Warren in the South Carolina runoff and Donovan in New York easily beat former congressman Michael Grimm, who was fighting to win back his old seat.

"Tremendous win for Congressman Dan Donovan," Trump wrote on Tuesday. "You showed great courage in a tough race!"

"Congratulations to Governor Henry McMaster on your BIG election win! South Carolina loves you," he added on the governor's race. "We are all proud of you and Peggy!"

Questions about Trump's endorsement power remain -- several candidates the President has backed have failed to win -- but Tuesday was a good night for the President.

Senator Romney?

Romney, the onetime GOP presidential nominee and Trump foil, won Utah's Republican Senate primary on Tuesday night, taking the next step in his political rebirth.

The win presents an intriguing scenario: Romney, the onetime Republican Party standard bearer, with a perch in Washington to both help and torment Trump, the current Republican standard bearer.

Romney has run in Utah as both a friend and a foe to Trump, promising to stand with the President when it helps the people of Utah and opposing him when it does not.

"I do not make this a daily commentary," Romney wrote in the Salt Lake Tribune during the campaign. "I express contrary views only when I believe it is a matter of substantial significance."

And he has tried to live that, most recently with the President's plan to separate children from their families at the US-Mexico border.

"If he's going to say something that's right and good for the country, I'll be all for it," Romney said in an interview with CNN. "If he says something I don't feel is right, well I'm going to feel obligated to speak my mind because if the captain of the team says something that you think is seriously wrong, why unless you say something, it suggests you're going along with something that might have been said."

Trump ignored their checkered relationship on Tuesday night, congratulating the former governor on a "big and conclusive win."

"I look forward to working together - there is so much good to do," he wrote on Twitter. "A great and loving family will be coming to D.C."

Jealous prevails in Maryland

Former NAACP President Ben Jealous emerged from a crowded field in Maryland to win the Democratic nomination to challenge incumbent Republican Gov. Larry Hogan.

Jealous could become Maryland's first African American governor if he wins in November, but Hogan's popularity has soared since he was elected four years ago, landing him among the most popular governors in America.

Jealous' run against Prince George's County Executive Rushern Baker garnered significant national support, with the progressive leader garnering endorsements a series of possible 2020 Democratic contenders, including California Sen. Kamala Harris, Vermont Sen. Bernie Sanders and New Jersey Sen. Cory Booker.

"Ben Jealous is the right candidate to win back Maryland for the Democrats, and the DGA looks forward to working with him to do so," Democratic Governors Association chair Jay Inslee said in a statement.

Money helps

As The Beatles once sang, "money can't buy me love."

But, on Tuesday night, Democrat David Trone proved it can help land you a run at a House seat.

Trone, who spent $13 million and lost to now Rep. Jamie Raskin in 2016, won the Democratic primary in Maryland's Sixth District on Tuesday after spending more than $10 million of his own fortune.

It's a lot of money, but the co-owner of the retail chain Total Wine & More has his shot at winning the solidly Democratic seat in November.