During a news conference on Monday, Sen. Lindsey Graham (R-S.C.) called for an investigation into whether or not special counsel Robert Mueller's investigation was "opened as a back door to spy on the [Donald] Trump campaign."

What's the story?

Graham told the media that he was "concerned" with how the Russia investigation was handled.

"It seems pretty bad on its face," he said.

He said during the course of the investigation, the FBI had been guilty of "shady behavior." He said he thought that "Donald Trump got scrutinized like nobody in the history of the presidency, since [Richard M.] Nixon probably."

Graham said he hoped that Attorney General William Barr would appoint a second special counsel, in order to determine "whether or not the FISA warrant process was abused for political purposes" and "whether or not a counterintelligence investigation was opened up, regarding the Trump campaign, as a back door to spy on the campaign."

He said that this person conducting this follow-up investigation should be "somebody like a Mr. Mueller."

Graham argued that if there was genuine concern that people on the Trump campaign were working with Russia, that Trump should have been warned. He contrasted this to the way in which the government alerted Sen. Dianne Feinstein (D-Calif.) to the fact that her former driver was suspected of being a spy for the Chinese government.

"Was it a ruse to get into the Trump campaign?" he continued. "I don't know, but I'm going to try to find out."

What else?

This echoes a tweet that Graham sent on Sunday. Shortly after Barr released a letter summarizing the Mueller report, former FBI Director James Comey had tweeted a picture of himself staring at towering trees in a forest with the caption "So many questions." Graham retweeted that picture and added "Could not agree more. See you soon."