You are entitled to your own opinions on politics - and so is your husband! It can be awkward if they don't always match up, but it sounds like your husband needs to get over that a little.
I would talk with him and say " Honey you seemed upset that I went to the meeting to support so-and-so. Can we talk about that? I don't want to argue with you about it, but sometimes we might just have to agree to disagree. My supporting a political candidate doesn't have anything to do with us loving and supporting each other, right?"
Put like that, he ought to at least discuss it. Don't try to change his mind if he doesn't support your candidate- just focus on the 'agree to disagree' . This approach has worked well in my family of mixed Dems, Repubs and Independents!
If, on the other hand, he was just grumpy about watching the kids, then THAT is a whole other conversation!