I don't have a dog in this race - I am not even from the US.
But, by definition, not voting is an action rather than absence of one. What you are doing by not voting is giving out a tacit agreement that the people who went and vote get to decide who will be elected.
Following that line of thought, by not voting, you actively chose the current government, no matter what the current government is.
Voting blocks are just simplifications of reality. Following that line of thought too far leads to bad arguments. The full truth is that any individual voter has a negligible effect on the outcome of an election.
I agree, but there are many who say that not voting is the only way to show contempt for a system rigged against them. Voting would be a tacit endorsement and recognition of the legitimacy of that system.
Those that don't care to vote are doomed to be ruled by those who care.
You still have to pay taxes, and perhaps see a government you truly despise making all sorts of decisions that will get the system even more rigged against you.
Not voting out of spite is similar to stabbing your own head to show contempt for your brain when you have a migraine.
Not voting, practically, is empowering the status quo. Particularly in America, where almost every election features intense down-ballot competition.
Someone who didn’t vote is more in concordance with the current government than someone who voted against it. Actions speak louder than words, and not voting is an action.