There are a lot of reasons that contribute to an email being marked as spam. We can generally divide these into technical things that the technology should address and the non-technical things that fall more on the sender.
Assuming you are using an email system that manages all the technical aspects around opt-out, delivery and sender validation, then deliverability starts to become the domain of the sender and within that, there are a number of things that can greatly reduce your deliverability. Here, we will talk only about the use of words in your email can increase the chances your email will be gently guided to the junk box, which is using spam-trigger words.
Of course, the greatest defense against a spam-trigger word causing you problems is to have a positive track record of delivering emails -- on a regular basis -- that are wanted and interacted with by your audience. Having said that, here are some words that are not uncommon to social and political causes that can trigger the spam filter. Try to avoid these when possible.
This is just a partial list and it's mostly filtered to words commonly used in political or social emails. While not a complete list, It should give you a decent understanding of words that can trigger spam filters. Remember, avoiding these words becomes MUCH more important for new senders that do not have a successful history of sending to an engaged audience.