Anytime one advances a cause with lies or obviously bogus statistics one's commitment to truth is obviously called into question. In addition, if someone knowingly uses fake statistics to try and demonize a particular group it demonstrates he/she is not only a liar but a bigot as well.
A few years back Wee Willy Bennett kept repeating some obviously fake statistics about the average lifespans of gay men. When confronted with the fact that the methodology used to obtained these numbers was flawed in a way which would be obvious to your typical 9 year old (and probably obvious to Brad Delong's kid when he was about 3), Bennett refused to back down. Instead, he cited another source to back up his claims - a source which simply cited the flawed original numbers.
Bennett - bigot, liar, hypocrite.