[ethanbond]

"this statement" = "As we all try to understand what this vote means to us, I want to affirm to anyone on our team that is scared or feels personally exposed, that I and everyone else here at Grubhub will fight for your dignity and your right to make a better life for yourself and your family here in the United States."

Basically, if you don't feel like you can be part of the "everyone here at Gruhub [who] will fight for your dignity and your right to make a better life... in the United States," you don't belong. Nothing about the act of supporting Trump, per se.

[Merem]

What he says at the core is perfectly fine. His mistake is politicizing the message when there is no need for that and hinting at a connection between Trump becoming president and that the people who voted for him likely don't support what is written in the e-mail.

From an outsider's perspective: The reason for that might stem from the fact that this election was fought like a war, as in, they demonized the enemy. This was especially strong when it came to Trump. So now that the election/war is over, some people can't go back to view the "other" side in a rational way. For them, that side is still exactly everything the media told them it is and I believe that is the case here.