In Germany we’ve something we call “wehrhafte Demokratie” which basically means a democracy capable of defending itself. There are measures in place (in theory) that prevent parties that aim to destroy the democracy from getting into power by winning elections.

Someone who openly admits his goal is to end democracy shouldn’t be able to run for president. It’s what happened in Germany back in 1933. The NSDAP won the general election and took over the government via democratic means and within weeks destroyed the democracy. Never again (hopefully)