Conservative radio host Erick Erickson on Monday equated the political left in the United States to the Islamic State in Iraq and Syria (ISIS) and said states should "start talking" about secession.

"The political left is becoming the American ISIS," Erickson wrote in a post on his blog. "Evil preaches tolerance until it is dominant and then it seeks to silence good. Evil is now dominant - but the partisan line is blurred."

Erickson said liberals show "no signs of toning down" their hateful rhetoric even after a gunman opened fire on GOP lawmakers who were practicing last week for a congressional baseball game.

"Too many [liberals] regret there were no deaths" from the baseball shooting, Erickson wrote, adding that the left believes House Majority Whip Steve Scalise (R-La.), who was shot, "deserved it."

Erickson said the right should not be excused, saying it is all but possible that "some nut on the right" could decide "to seek vengeance for Republican congressmen."

He pointed to what he says are movements started by left-wing ideologies.

"From Nazism to Communism to progressivism itself, there has been more butchery from leftwing ideologies throughout human history than from the right - and yes despite popular historic revisionism, Nazism is from the left and had an American progressive fan club that included Margaret Sanger, patron saint of killing kids," Erickson writes.

Erickson says federalism and the ability for states to push for their interests does not appear to be working because "the minority nows gets to exert its will over the majority."

"The only escape is dissolution. We should part ways if we cannot have federalism. We should start talking about secession. If both sides have decided that every hill is a hill to die on and control of Washington means reward for their friends and punishment of their enemies, we need to end Washington. The way to do that is end the union," he adds, saying he is no longer "an optimist about the future of this country."

"Both sides are out for blood. The only way to calm the situation is for us to part ways," Erickson concludes.