However your quality of life in society is much more important than any single issue. Knowingly voting for a candidate who is not competent just because you agree with them on a single issue will not solve any of the larger issues in society.
Consider you have to 2 groups, A and B, and a set of issues. Each issue has different importance to me and each group has a generally opposing stance on each issue.
One group may have a stance on a subset of issues I generally prefer but more importantly the other group could have a stance on issues that terrify me. Their stance would lead to negative outcomes much worse than negative outcomes from the other group. It could even be that I disagree with many of the stances of the group I vote for but I’m not terrified of the outcomes associated with those stances.
So it is therefore more important to win to stop the opposition group from producing undesirable outcomes.
Unless, of course, you don't believe in democracy and an election process.
…assuming you trust the system to enact policies you care about. Punishing the act of disingenuously eroding trust in the system for political gain isn’t just a matter of principal but a clear long term strategy. Believe it or not there’s another election cycle after this one.
The winning at-all-costs attitude is what got us here in the first place: people so concerned with winning and having their people in office they don’t care if they actually won the election, and tell themselves increasingly nonsensical things to justify it.
The book “Rules for Radicals” talks about this and it has been a tool of left wing activists for 60+ years. You see it today for instance with various activists groups that plea for “our democracy” on one hand while destroying things and disrupting society until they get their way outside the democratic process.
That seems like a meta issue, that if not supported, all other issues are moot. So I'd certainly vote against party on any given platform plank in order to maintain the meta process that applies to both present and all future parties regardless of platform planks.