I told Sen. Feinstein she was the most disappointing politician to ever represent me and the first I regretted voting for, after pointing out she's been in the Senate longer than I have been alive. She actually did what I asked and stepped down from the minority leadership in the Senate Judiciary committee. I wasn't the only one who said something.
SOPA is an older example, politicians do actually listen. Defeatism will not get you anything you want.