That is the problem is two fold; a large number of Americans who are deplorable combined with a political party anxious to exploit these deplorables for personal gain.
Or as Paul Krugman put over a year ago:
"How did we get here? The core story of U.S. politics over the past four decades is that wealthy elites weaponized white racism to gain political power, which they used to pursue policies that enriched the already wealthy at workers’ expense.
Until Trump’s rise it was possible — barely — for people to deny this reality with a straight face. At this point, however, it requires willful blindness not to see what’s going on."