Two Democratic lawmakers called for President Donald Trump to be removed from office after his remarks Tuesday defending some protesters at a white nationalist gathering in Charlottesville, Virginia, last weekend.

Trump said there was “blame on both sides” at a news conference on Tuesday and there were some “very fine people” protesting on the same side as the white supremacists.

California Democrat Jackie Speier, who replaced Holocaust survivor Tom Lantos in the House in 2008, tweeted that the president was “showing signs of erratic behavior,” in her call to invoke the 25th Amendment of the Constitution, which says that if a majority of Cabinet officers and the vice president say the president is unable to serve, he may be removed from office.

POTUS is showing signs of erratic behavior and mental instability that place the country in grave danger. Time to invoke the 25th Amendment. — Jackie Speier (@RepSpeier) August 16, 2017

Speier also tweeted a quoted from the French philosopher Voltaire: “Those who can make you believe absurdities can make you commit atrocities.”