You want everyone on your side.
There is an argument to be made to everyone that will get them to act on your behalf. It’s just a matter of listening and alignment. If a person’s personal values and beliefs do not match your own, find the areas that do line up.
Some people are irredeemable or irrelevant to a given conversation. Treat them with respect, but do not concentrate your efforts on them. Most people who are even in the conversation related to your cause are “turnable.” They can be convinced. You can find common cause. It’s really only a matter of time and persistence.
Political party affiliation can often be largely irrelevant, especially on local issues (unless your cause intersects a core issue or culture war issues). Locally speaking, people are far less likely to pontificate. They are all too close to the subject matter to not engage with the actual specifics, and there are cases to be made to people of all political persuasions. At the end of the day, people are byproducts of their upbringing and are invested in their local communities… the ones who aren’t complete shills.
Even the total political frauds have a utility: they will line up for an opportunity to be seen as linked to a good cause, and yours is one.