There is no good answer to this question. Most hecklers are jerks. OTH, the emperor needs to be told loudly and often that he has no clothes.
The rep that called Obama a liar was quite correct. So also are those who also called Bush, Clinton... liars.
I find it amusing that all the liberals are so incensed that Obama was called a liar, when they went non-stop after Bush.
As far as I'm concerned, a pox on both their houses.