It’ll notably look exactly like what you’re exasperated about though. “We’re definitely going to vote for you but we’re angry” is shorthand for “ignore me”.
Only if the whole “representative” part of democracy is a sham and a joke. I don’t think it is.
This sounds like you believe telling a representative that your vote is assured but your angry with their choice will get them to take your concerns seriously unless the “representative” part is a sham, but there’s no inherent expectation of goodness in a representative democracy. If they don’t want to do something and you (and all your allies) tell them “we want you to change your position, but we’re going to vote for you regardless of what you do”, you’ve told them all they need to know, because ignoring you won’t cost them any votes and presumably the other choice either will or is just what they’d like to do.
“Representative” democracy just means we hand over immediate power to the people we vote for to do the day to day governing. It doesn’t mean they actually innately represent their constituents nor does it involve just guessing who’d be best every four years and then sitting back and hoping it goes well.
Politicians ignore their constituents all the time. I’m glad that Biden doesn’t give a fuck that some pro-life zealots are big mad that he doesn’t ban abortion. He knows they have almost no chance of voting for him and it would lose him a bunch of his actual voters. But if we all got together and said “hey Joe, don’t worry about what we want on abortion, we’re 100% with you regardless”, he might start thinking about softening his stance on abortion bans to pick up a few more votes from the zealots. You can leave the threat to not vote for them unsaid, but the threat is what gets them to change their stance, and if you preemptively rule out ever taking away the thing they want in the transaction, they have no reason to do so.
Votes in exchange for policy is the whole deal. There’s no requirement in a functioning democratic system for the representatives to just do stuff out of innate goodness.