Never have those allegations been given more weight than this year. Trump isn't the only Republican to have made the suggestion, for a start. Many other Republicans haven't said anything at all, and silence can be often taken as implicit agreement (rightly or wrongly). And, given that 74 million people voted for him, there are clearly a lot of Americans who still take seriously what he says, or at least are willing to tolerate it.
Let's hope you are right and it is a mere blip, but it is still important not just to say that Trump is wrong but to condemn him loudly for making these baseless allegations.