Trump's bluff and bluster would collide with reality if elected
Many voters fear that a President Donald Trump would be a despot. Trump's authoritarian streak, colossal ego, and disdain for limits would spell tyranny, they worry.Trump does appear to be blissfully ignorant of the limitations of power he would possess if President. It would require a constitutional amendment to "open up the libel laws." He does not have enough popularity to get a majority support for such a change, much less the super majority needed to get an amendment passed. If he attempted to live up to many of his other promises, he would likely be impeached. That is something that you would never have to be concerned about in a Ted Cruz administration.
This fear is misplaced. Donald Trump couldn't be a tyrant even if he wanted to. Instead, Trump would be an incontinent windbag whose ignorance, self-regard, and lack of self-restraint would produce a daily string of embarrassments. Some of these would be destructive and dangerous to the country and the world. That's the real reason good people should fear a President Trump.
Trump very well might have authoritarian and tyrannical aspirations. He certainly speaks as if he does. His economic plan largely involves calling CEOs and threatening them with punitive tariffs targeted at their businesses. This fits into the governing style he promises: ad hoc deal-making. From what we know about him, this would evolve into self-serving cronyism, in the most literal sense of the word, if Trump had his way.
Beyond economics, Trump sounds scarier.
He has promised to "open up our libel laws," to go after critical journalists. He has advocated torture and threatened to punish military personnel who refuse his unlawful orders. Trump says he would kill the wives and children of terrorists, which is also illegal. In fact, it's a war crime.
Many voters like these strongman ideas, which is why Trump is popular. But they clash with the principles of American government, where the rule of law and the rights of the individual are foundational.