I'll leave it to others to decide exactly where to draw the exact dividing line is between everyday rightwing craziness and out-and-out fascism, but it never hurts to be reminded of this admonition attributed to Sinclair's Lewis. There certainly were plenty of flags. And no shortage of speakers spewing the usual over the top rightwing vitriol, often attacking their political opponents' personal hygiene and grooming -- a common rightwing means of dehumanizing those with who they disagree that seems to say more about the speakers than those with whom they disagree.
Note: The quote is often attributed to Sinclair Lewis, and in particular his 1935 semi-satirical novel about a fascist take-over in America, and sometimes to Upton Sinclair or H. L. Mencken. In fact, nobody has been able to trace this quote to any of the three authors. As happens so often with famous quotes, it often starts with something said by somebody not famous that gets attributed to someone more famous, and then polished over time (the same thing happened with Vince Lombardi's "quote" about winning). In the case of the Lewis quote, it seems to have started with something journalist Harrison Salisbury wrote in 1971 about Lewis. This natural evolution of quotes into increasingly polished and widely repeated misquotes is analyzed in Nice Guys Finish Seventh, a 1992 book by Ralph Keyes..