Sen. Lindsey Graham (R., S.C.) on Monday took issue with the notion that Justice Department Inspector General Michael Horowitz's report does not provide enough evidence to prove that political bias affected the FBI investigation into Hillary Clinton's private email server.

Graham said that the prevalence of investigators' bias against Donald Trump in the 2016 presidential election logically implies that they would seek to exonerate Clinton, his opponent at the time. The senator said there is enough circumstantial evidence to show that certain decisions were made with an eye toward helping Clinton.

After Horowitz, who released his report on the Clinton email probe last week, said repeatedly that text messages showing apparent bias had him "very concerned," Graham said, "Eventually, ‘very concerned' gets to be ‘enough already.'"

Graham pointed to a litany of messages in which the FBI's lead investigator on the Clinton case, Peter Strzok, expressed in private that he opposed Trump's election, including one message in which he said "we'll stop it." Graham said this belies the conclusion in Horowitz's report that prosecutors' decisions did not result from bias.

"I'm not buying that the Clinton investigation was on the up and up, and the reason I am not buying it is because the two people intimately involved, one, the lead investigator, clearly did not want to see Donald Trump become president of the United States," Graham said.

Graham also said further investigation is needed because former FBI Deputy Director Andy McCabe and Strzok do not appear to agree about a meeting in which Strzok discussed having an "insurance policy" against Trump's potential election.

"Someone is lying," Graham said of Strzok and McCabe. "So anyway, we will figure that out later. None of this is normal, folks."

Graham said all of the evidence also points to the logical conclusion that investigators did not want to find Clinton guilty.

"Finally, do you agree with me that finding her liable criminally would be inconsistent with stopping Donald Trump?" Graham asked. "If they found Hillary Clinton was criminally liable that paves the way for Donald Trump. Can you put those two things together?"

After quibbling about the time of the messages, Horowitz said, "It clearly could, conceivably."

"Not only ‘clearly conceivably,' that is exactly what is happening here, folks," Graham replied. "You cannot hold her criminally liable and ‘stop' him."

Graham also asked why "gross negligence" was removed from the statement about Clinton's actions. Horowitz hesitated, and started to speak when Graham interjected.

"Can I just suggest something? ‘Gross negligence' is a criminally liable standard. If they had said it the way they originally wrote it, she is guilty of a crime," Graham said. "If you want to stop him, it can't be ‘gross negligence.' What is the difference between ‘reckless disregard' and ‘gross negligence?'"

"Not much. It's pretty much —" Horowitz began.

"It's a lot politically," Graham said, referring to the difference.