[owenmarshall]

If you contact your congresscritter over their official congressional channels - email, phone, Twitter, plain ol' letter - and tell them you plan to vote for/against them because of $X, a very polite intern will tell you that they will record your support/opposition to $X but that they cannot pass along your comment on voting to your congresscritter.

Be sure to share that with their campaign: that's how you get that message through.

[dsfyu404ed]

They can't "pass along your message" specifically but when they get several hundred people saying they didn't vote for $boss because of their stance on $issue they will find a way to let $boss know about the pattern.