The best way to prevent tyrants is to have a strong Constitution.
I suppose I can understand your fear, since your side has been undermining the constitution...living breathing document which doesn't stop the president from acting.
With the Constitution (and strong federalism), a tyrant cannot be elected.
Without the Constitution (and without federalism), you need to make sure you win every election.
I see why you are worried. That is pure partisanship, though. You are fine if you win; you are not fine if your side does not win. That is the defining characteristic of a banana republic. That is what we are becoming. The way to fix it is to reform, and restore the constitution. The strategy of "electing the right people" will always fail over time. Flip a coin 50 times, and it will turn up tails at least once. Only a systemic block can stop tyrants.