From personal experience (your mileage may vary) calling them only ended up with my number being registered and spammed with conservative political donation requests.

If you happen to run into him when waiting in the airport to go to Mexico...... much better odds of having a chance to convince the actual person without getting spammed.

Still probably low odds though.

I definitely wouldn't write to a Republican about it. I was going to look at neighboring districts to find the closest couple of Democratic House reps.

not about leadership, since politically the opposite party is supposed to stay out of the other parties leadership choices.

But I would write to them (without saying you're x party) to tell them you care about accountability, affordablility and in general what you're in support of or against. like someone else mentioned you'll get a canned response but that tally tells them a bit more about what their constituents want (whether they listen is dependent on how threatened they feel when it comes to re-election).

You can write to them (email or paper) and it can apply pressure indirectly. Their interns read it and "tally" the types of issues mentioned. They will send you a bullshit canned response that re-states their already engrained positions, whether it aligns with what you want or not.

But arguably it can move the needle if enough people put sustained pressure around very specific bills. Probably more direct influence than voting.