The disagreements with the travel ban are not partisan or political — this ban will have very serious consequences for millions of people, and maybe more in the future, given what the president has said during the campaign. So far, he has delivered on his campaign promises, and has demonstrated that he cannot be reasoned with.
Some of us gave us him a chance, but now it's clear he's not going to change. If we don't take action now and prevent him from being normalized soon, it will be too late.
Nobody likes comparisons with Hitler, but I think in 30 years we may very well view Trump in a similar light — if I were there, I would've said something, why didn't anybody stop him?