Sen. Bernie Sanders on Monday hurled insults at President Trump in a fundraising email, ginning up support as he continues to mull the possibility of a second tilt at the White House.

"We are living in a truly unprecedented moment in history and the actions we take now, together, will determine not only the future of our country but the entire world. If there has ever been a time in American history when our people must stand together in the fight for economic, social, racial and environmental justice - now is that time," Sanders wrote.

The independent senator from Vermont, who caucuses with Democrats, added, "The bad news is that we have a president who is a fraud, a pathological liar and a racist. The good news is that the American people are standing up, fighting back and are demanding fundamental changes in our economic and political system."

Sanders, who unsuccessfully ran for the Democratic presidential nomination against Hillary Clinton in 2016, is rumored to be close to a decision regarding whether to run again. The 77-year-old senator has repeatedly said he would launch a campaign if he is "the best candidate to beat" Trump. Yahoo News reported last week that his presidential aspirations had been buoyed by a slew of early polls that showed him and former Vice President Joe Biden as the favorites to earn the party's nod.

Sanders has used similar language to describe Trump before. On Martin Luther King Jr. Day, he told a crowd in South Carolina that the president was "intentionally, purposely" "trying to divide us up by the color of our skin, by our gender, by the country we came from, by our religion."

"Today we talk about justice and today we talk about racism, and I must tell you it gives me no pleasure to tell you that we now have a president of the United States who is a racist," Sanders said.