Mother Jones has a compilation of some of the nasty Republican mailers and ads that are permeating party efforts this election year. We're not talking about Trump ads, but downticket efforts by the state parties and state candidates. A few are worth highlighting:
In October, the Kansas Republican Party sent out an ominous mailer posing the question "Have you met the new neighbors?" In the background is a hazy country landscape punctuated by an ISIS flag. In one corner is a sinister figure clutching an assault rifle, his face covered with a keffiyeh. The flier states, "The first step to keeping Kansas safe is to recognize who the enemy is...LET'S KEEP TERRORISTS OUT OF KANSAS!" The mailer was distributed two weeks after three white militiamen were arrested for plotting to bomb Somali refugees.
The suggestion that red-state America is being invaded by flag-waving ISIS militants—coming in posing as, you know, ethnic people, is not the slightest bit uncommon. It is the defining conspiracy theory of the party: a xenophobic insistence that America is Doomed if we let immigrants, or refugees, or dark-skinned people move into houses next to our own. It's frequently conflated with Mexican immigration (See: Sen. Tom Cotton, as good a poster child as any for the raw stupidity of the arguments) out of an apparent conviction that all not-white-enough people are in on the same plot, and it's just as often paired with suggestions that those brown people are also bringing in Ebola or other very scary diseases, possibly on purpose.
Kansas isn't the only state where Republicans are using the imagery of terrorists on your doorstep. And the while that specific premise is being borrowed from, of course, the National Rifle Association, chief propagator of paranoid xenophobic rantings about America's imminent doom at the hands of not-white people, it's plainly rooted in white nationalism. The notion that immigrants are dangerous; the notion that non-white groups are riddled with disease; the existential risk posed by a non-white person moving into your particular neighborhood are all among the most common of racist tropes.
And Trump didn't do that. If Republicans nationwide are cribbing from the arguments and imagery of white supremacist groups, it ain't Trump calling those shots. And it's not the first election in which Republicans have done it, and it's not going to be the last.
This is the party. It should say something that Trump can dismiss or degrade every other bit of policy Republicans have claimed to cling to over the years, but by becoming the presidential candidate most willing to broadcast that xenophobia openly he was able to easily defeat all other Republican comers. It's a base the party has catered to and cultivated for, literally, decades.