Republican presidential candidate Donald Trump slammed Democratic counterpart Hillary Clinton at a rally in Grand Rapids, Michigan, calling her a liar and using vulgar terms to describe her performance in the 2008 presidential race. Trump’s comments followed Clinton’s statement Saturday that he is the "best recruiter" for the Islamic State group.

"She's a liar," Trump said at the rally, which was attended by 6,000 people, adding that Clinton was "crooked" and "not a president." He also said that Clinton “got schlonged” by U.S. President Barack Obama during the 2008 presidential race. 

"Even a race to Obama, she was gonna beat Obama. I don't know who would be worse, I don't know, how could it be worse? But she was going to beat -- she was favored to win -- and she got schlonged, she lost, I mean she lost," Trump reportedly said.

This isn’t the first time Trump has used the expression while speaking about opponents. A report by the Guardian said that, in 2011, Trump blamed Paul Ryan, who is now the House speaker, for the party losing a special election, saying: “I watched a popular Republican woman [Jane Corwin] not only lose but get schlonged by a Democrat [Kathy Hochul] nobody ever heard of for the congressional seat and that was because, simply, because of the Paul Ryan plan.”

Trump, while talking to reporters later, also mocked Clinton for returning late to the debate from a restroom break, according to CNN. "I know where she went, it's disgusting, I don't want to talk about it," adding: "No, it's too disgusting. Don't say it, it's disgusting, let's not talk, we want to be very, very straight up."

According to the Associated Press, Clinton accused Trump Saturday of making comments that would help ISIS' recruitment drive, stating: "They are going to people showing videos of Donald Trump insulting Islam and Muslims in order to recruit more radical jihadists."

Although there was no evidence to back the claim, Clinton’s spokeswoman said, "She didn't have a particular video in mind," but reportedly refused to take back Clinton’s comments.

Trump also criticized several other political opponents during his speech, including Obama and Sen. Lindsey Graham, who opted out of the presidential race Monday.

"Ask Jeb Bush if he enjoys running against me. Ask Lindsey Graham, did he enjoy running against Trump? Ask Perry, ask Gov. Perry. Ask Bobby Jindal," Trump said, according to CNN, adding: "Ask all of these guys that have gone out, do they enjoy running against Trump? I enjoy it. They don't enjoy it."

In August, Trump also faced severe criticism for implying that Fox News host Megyn Kelly asked him difficult questions on air because she was menstruating.