Get involved. Call your local, state, or regional Democratic party office and volunteer. Or volunteer for a specific candidate. Go out, knock on doors, make phone calls, distribute fliers. Donate money. Call for donations. Help stuff envelopes.
While you're doing this, be kind. Always be kind. Be thoughtful. It's a cliche of sorts that the difference you make to one person is the most important, but it truly is. Just look at Donald Trump to see why it's so important to be kind. Look at what he has created, and brought up from the muck just by encouraging harshness, violence, and cruelty. And not just his words, but his policies.
“Be careful hunting monsters, lest you become one yourself, for when you stare into the Abyss, the Abyss also stares into you.” -- Nietzsche.
Sure, Nietzsche was a syphillitic douchebag, but he also had a lot of words of wisdom, so we'll quote him on that one.
Don't argue with people online. Share your thoughts, but don't stoop to their level. Be thoughtful and kind, and speak as if you're talking to someone who, somewhere in there, at least, can listen. Don't react. Respond. And never trade insults.
Humor helps me deal with all of this. I save the harsh humor for between me and my friends, where we're all on the same page and know where we're coming from. But gentle humor out in the world can make a huge difference in interactions.
Of course all this is hard, that's why more people dont' do it. That's why you and I don't do it all the time, despite how much we'd like to. But the only way out is by being something different than what you're trying to change, or they will assume that at base you are just like them, only with a different perspective.
And while as humans, we are "just like them," we are trying to follow our better angels and inspire fellow humans rather than just follow in their footsteps of "pissing off the liberals," only the other way around.
Be better than that because you are better than that.
But never forget to get involved in electoral politics, too. Without that, the present and near future can be lost.