Is this in reference to her show in Atlanta on Saturday? I was at that show and did see a large number of people walking out when she started getting political. She attempted to bring a Trump supporter on stage who was yelling at her but he wouldn't budge. I saw another rather drunk and loud heckler (I'm assuming he was heckling about Trump) get escorted out.
I am by no means a Trump supporter, but I do think she made a mistake by stereotyping all Trump supporters as gun-toting redneck racists during her show. If you are geniuinely trying to bring people to your side, that tact is only going to make people dig their heels in even harder, especially in the deep south. And that can be said about both sides of this election. It just does nothing to help actual political discourse, if that is in fact what she wants to have.
But back to Schumer: She did say that she knew doing that and going political was going to likely cost her fans and that she didn't give a ****, and I believe her. She has a stage and that is how she has decided to use it. There will be enough people leftover that will be fans of hers that she will be fine. She may not be able to sell out Phillips Arena anymore, but she will still have a career.