U.S. President Donald Trump speaks to reporters as he departs on travel to Dayton, Ohio and El Paso, Texas following back-to-back mass shootings in the cities, from the South Lawn of the White House in Washington, U.S., August 7, 2019. REUTERS/

Trump next set his sights on Sen. Sherrod Brown, D-Ohio, and Dayton Mayor Nan Whaley, also a Democrat, who gave a news conference earlier this afternoon after Trump left the city. Trump called Brown a "failed Presidential Candidate (0%)." Brown had ruled out a 2020 presidential bid.

Biden is the front-runner for the Democratic presidential nomination.

While in flight, Trump took to Twitter to attack 2020 presidential candidate and former Vice President Joe Biden – who was giving a speech on white supremacy that criticized Trump's rhetoric – as "sleepy" and "sooo boring." Trump said that a Biden presidency "will be one big crash, but at least China will be happy."

Just days after calling for unity in the wake of two mass shootings over the weekend, Trump lashed out at his Democratic opponents and a media figure en route from Dayton, Ohio, to El Paso, Texas, where he was slated to meet with survivors of the shooting there.

Trump also accused Brown and Whaley, who has been a vocal critic of Trump's response to the weekend's shootings, of incorrectly describing his interactions with survivors of the shooting during his visit.

@realDonaldTrump: ....misrepresenting what took place inside of the hospital. Their news conference after I left for El Paso was a fraud. It bore no resemblance to what took place with those incredible people that I was so lucky to meet and spend time with. They were all amazing!o

"I've said before Donald Trump is a bully and bullies are cowards. I don't care what he says about me," Brown said in a statement. "But the people of Dayton deserve a President more focused on protecting them from gun violence than protecting his own ego."

A Cincinnati Enquirer reporter recorded Whaley's response to Trump's tweet and posted it on Twitter.

"I don't know what they're talking about misrepresenting. Oh well, you know, he lives in his world of Twitter," she said of the president.

Ohio tweet

Trump then took on Fox News host Shepard Smith, who has been more skeptical of the Trump administration and the president than several other hosts on the network, particularly its prime-time opinion show hosts. Trump mocked Smith's ratings and said he preferred to watch One America News Network, a smaller right-wing news network which has been strongly pro-Trump.

@realDonaldTrump: Watching Fake News CNN is better than watching Shepard Smith, the lowest rated show on @FoxNews. Actually, whenever possible, I turn to @OANN!

Smith acknowledged and brushed off Trump's tweet on air, remarking, "Good afternoon, Mr. President, it's nice to have you with us," before continuing on with his broadcast.

Some Trump staffers also went on the offensive. White House social media director Dan Scavino also had harsh words about Brown and Whaley, calling them "disgraceful politicians, doing nothing but politicizing a mass shooting."

@Scavino45: Very SAD to see Ohio Senator Brown, & Dayton Mayor Nan Whaley - LYING & completely mischaracterizing what took place w/ the President's visit to Miami Valley Hospital today. They are disgraceful politicians, doing nothing but politicizing a mass shooting, at every turn they can..

Representatives for Biden and Whaley did not immediately respond to CNBC's request for comment.

Air Force One landed in Texas just before 4:30 p.m. ET.