More than an hour after the Democrats' 2020 field wrapped up its second debate in Detroit Wednesday night, President Donald Trump finally took direct aim at his White House rivals.

"The people on the stage tonight, and last, were not those that will either Make America Great Again or Keep America Great!" the president tweeted shortly after midnight on Thursday. "...We have prosperity & success like never before.."

"...It will soon be time to choose to keep and build upon that prosperity and success, or let it go," he added. "We are respected again all around the world. Keep it that way!"

His campaign quickly claimed victory. "Goodbye Pennsylvania. Goodbye auto industry. Goodbye Midwest," campaign spokeswoman Kayleigh McEnany tweeted as the debate ended. "Another win for President @realDonaldTrump."

As the candidates debated in Detroit a few hours earlier, Trump had first directed his fire not at the contenders running to replace him, but on his predecessor, falsely claiming that Barack Obama had employed a family separation policy at the U.S.-Mexico border.

Trump tweeted the accusation soon after the debate discussion turned to the situation at the border and the nation’s immigration policies.

The cages for kids were built by the Obama Administration in 2014. He had the policy of child separation. I ended it even as I realized that more families would then come to the Border! @CNN — Donald J. Trump (@realDonaldTrump) August 1, 2019

Trump appeared to refer to the 2014 border crisis involving unaccompanied minors entering the U.S. in dramatic numbers, in which the Obama administration housed children in run-down facilities as well as a large center in McAllen, Texas, that contained chain-linked fencing, according to The Associated Press.

But the president's statement about the family separation policy was inaccurate; NBC News has previously reported that there was no widespread policy under the Obama administration of separating migrant parents and children.

Trump instituted a “zero tolerance” immigration policy last year that involved trying to prosecute every illegal border crossing, including those who were seeking asylum. That policy led to the federal government separating children from their parents or legal guardians because the adults had been referred for prosecution for illegally entering the country.

As a result of a preliminary injunction issued by a federal judge, though, the Trump administration was ordered to halt the policy last year. But the ACLU contended in a court filing this week that more than 900 children have been separated from their parents after it was supposedly stopped in 2018.

Just minutes before the start of the Wednesday debate, which included former Vice President Joe Biden and Sen. Kamala Harris, D-Calif., Trump tweeted that the facoff the night before had received “very low ratings” and suggested that people were “desperate” for Trump.

Very low ratings for the Democratic Debate last night — they’re desperate for Trump! — Donald J. Trump (@realDonaldTrump) July 31, 2019

CNN announced Wednesday afternoon that the network's first debate of the campaign cycle on Tuesday evening had attracted 8.7 million viewers, a significant drop from the 15.3 million viewers who watched the first night of the Democratic debate in Miami last month that was hosted by NBC, MSNBC and Telemundo.

Earlier in the day Wednesday, Trump said that Democrats would lead the nation “into an economic sinkhole,” specifically taking aim at Biden and Harris.

"If I hadn’t won the 2016 Election, we would be in a Great Recession/Depression right now," he tweeted. "The people I saw on stage last night, & you can add in Sleepy Joe, Harris, & the rest, will lead us into an economic sinkhole the likes of which we have never seen before. With me, only up!"

Later in the day, he criticized CNN anchor Don Lemon for a question he asked during the first debate, which that featured several top candidates, including Sens. Bernie Sanders of Vermont and Elizabeth Warren of Massachusetts.

“CNN’s Don Lemon, the dumbest man on television, insinuated last night while asking a debate 'question' that I was a racist, when in fact I am 'the least racist person in the world,'" tweeted Trump. "Perhaps someone should explain to Don that he is supposed to be neutral, unbiased & fair, or is he too dumb (stupid) to understand that."

Despite tweeting frequently recently, and saying that he planned to watch the first debate, he remained silent on Twitter throughout Tuesday night's showdown.