In this election? Everything. One party wants to stick to traditional american values and ideology (capitalism, liberty, personal responsibility, the idea of american exceptionalism, etc.) The other is pushing for european style socialism(government is primarily seen as a caretaker for citizens rather than citizens taking care of themselves, rolling back of liberties in the name of safety or security, heavier regulation, etc) and when it comes to the GND basically a complete overthrow of the system that grew us from backwater colonies to the center of the world. This election is basically a choice between a multi party capitalist republic vs a one party socialist "democracy"