The tradgedy of Trump's first term was that the House of Representatives undermined the legitimacy of that check by using it in partisan, ambiguous and non-compelling circumstances, and failing as a result to obtain a conviction. Using the heavy machinery of impeachment ineffectively made it harder to use should the executive take the tremendous steps you're suggesting.
Anyway, Trump just mocked the leader of a foreign ally for refusing to hold elections. Viewed together, his comments sound like an extended troll of the political opposition.
Say what?!
It's Congress keeping the President in check. BTW, the President is not directly elected by the people and doesn't actually [directly] represent them. The President is elected by the state governments (legislatures) and is supposed to be chosen because the States belief the President will faithfully uphold the Constitution and the laws passed by Congress. It may happen the the States use a popular election to choose their electors that elect the President, at least for now, but the President isn't supposed to represent "the mob" (majority or the populace). It's also why the electoral college is used for electing the President rather than straight popular vote.