You’re not reliable because you hang around a particular political party urging it to advance your cause.
When, for whatever reason it cannot advance your cause to the extent you want it advanced, you bail. You quit.
You tell the party, “hey, this is where I get off. Good luck with that election!”
Why would any party even want to try to accommodate your views knowing that, even if the best efforts were made and circumstances were beyond the party’s control, if you didn’t like the result, you’d quit?
Not only quit, but actually undermine the party by, in essence, voting against its candidate?
You are weird. :)