It all depends on what you are trying to say
If Tom or anyone else has a cartoon view of liberals then it is wrong. That does not mean that even moderate liberals don't have that cartoon view.
In the case of his comment to ER, (who may have just been poking fun) you have a moderate liberal who gave the impression that he thinks religious conservatives are sexually backward. That is certainly cartoonish.
While it may be true that some religions may be "meat and potatos" when it come to sex the notion that not caring for sexual shushi is backward is incorrect and not even an issue when you are talking about Viagra.
IMO, without getting nittpicky sex is not political or philosophical it is a basic instinct and a great equalizer.