Jefferson’s informed electorate

Founding Father Thomas Jefferson wrote that a well-informed electorate is a prerequisite to democracy. How well informed and educated were people who voted for Donald Trump? After having seen what little good Trump has been able to do, except for himself and immediate family, and how much damage he has already done, many have come to regret how they cast there vote.
Jefferson also said that democracy is 51% of the people taking away the rights of the other 49%, – in contrast to the last election, where Donald Trump only got 46.1%, or about 3million votes less than his opponent, Hillary Clinton, still taking away the rights of the remaining majority.
It will probably remain a mystery why so many could vote for a sexual assaulter, an habitual liar, childish name caller and several times bankrupt, who didn’t seem to know much about the US Constitution, government’s role in a society, or what it takes to maintain the US position as a world leader and a model for the rest. Just insisting for 5 years that President Obama was born in Kenya, was so silly that such statements alone should have made him ineligible for any governmental post.

How could this have been prevented? Should presidential candidates be required to show their tax returns, go through a thorough background check, and be subjected to an in-depth examination about various topics to demonstrate a certain level of understanding?
It shouldn’t be enough to refer to the Bible as the favorite book, or that the tax return is stuck in audit. For starters, it would help to abolish the electoral college, an anachronism that made the last two Republican presidents possible, – Bush with 271, Trump with 304, while Obama gathered 375 electoral votes and 52.7% of the popular vote.