Head the letter as from, the people. No capitals.
Sign the letter as from, the people, then your name.
I will gladly write one, or ten, or twenty letters a day, as required. I have plenty of paper and a box of 1000 recycled envelopes. I'm ready to go.
We should write him a letter pointing out that he'd better do that or we'll do everything we can to see that he is not re-elected. I'm writing that letter soon as I finish this. Care to join me?