If you are going to raise money, you will be most effective doing it by asking people that have money to spare. Very wealthy people are the best ones to hit up, because they are least likely to get ticked off at you.
It is my observation that if I donate any amount of money (I suppose below the maximum allowed) my donation will be followed by a very brief thank you and another invitation to donate still more money.
My name will be sent to other candidates, and each and every one will call me and ask for even more money. Eventually, every dinner will be interrupted with clowns asking me for money, and that is when I just make one donation.
This is I think, a problem Barbra Streisand does not have, She donates the maximum, and she has "people" who answer her phone. If Barbra tells some solicitor not to call, they will tell the rest to stop calling.