Nothing prevents you from supporting better candidates. But you should always support a better (or less shitty) candidate in a primary/election where possible.
Canvas for the politician you prefer before the primary, then vote for them if they make it into the primary. If they or whatever other candidate you like less makes it into the general, voting for them is still better than voting for the party running a candidate that would be worse.
Meanwhile, doing the above does not prevent anyone from trying to organize protests to throw out the system and replace with a new one, or support an alternate party, although the tipping point for where it makes sense to vote for a third party is difficult, because any time people vote enough for a third party such that the less-evil party also loses, everyone loses.
Nothing prevents you from supporting better candidates. But you should always support a better (or less shitty) candidate in a primary/election where possible.
Canvas for the politician you prefer before the primary, then vote for them if they make it into the primary. If they or whatever other candidate you like less makes it into the general, voting for them is still better than voting for the party running a candidate that would be worse.
Meanwhile, doing the above does not prevent anyone from trying to organize protests to throw out the system and replace with a new one, or support an alternate party, although the tipping point for where it makes sense to vote for a third party is difficult, because any time people vote enough for a third party such that the less-evil party also loses, everyone loses.