How do people tolerate the "flim-flam jerk"? (Bo was being rhetorical, but I'll answer anyway)
One, information bubbles. In the post-truth era, people look to whomever they've been told is a strong person. It's anachronistic tribal thinking, hardwired into humans, which excludes all contrary data. One you drink the kool-aid of Trump-as-powerful, then you simply reside in the tweet bubble and the faux news bubble.
Second, fear. Achtung and all that. Even if you know the flim flammery truth, self-preservation inhibits action and speaking out. Especially in the red states, where the maga-maniacs are in control and many heavily armed. So you hunker down and console yourself and others with this too shall pass... A nice little opium dream.
Three, raw stupidity. We, as a nation, have been letting our public schools erode, and an electronic culture that favors soundbites over critical thinking and in-depth analysis has not helped. Corporate culture loves a soundbite world, which is a perfect growing medium for uncritical acceptance of consumerism. Soundbite thinkers are easy to sell fungible junk to. They're also easy prey to racist memes and simplistic campaign platforms about fearing the Other.
Four, lethargy and complacency. Many Americans breathe bad air, eat shitty food, and embrace a car culture that deprives them of the most minimal exercise. They are thus tired and passively willing to go with the flow, no matter how foul that flow may be. The sci-fi film "Wall-E" wasn't about the future, it was about right now. (as are most sci-fi movies)