"Calling someone a bigot does no good whatsoever, "
Yes it does - it draws attention to their bigotry and helps build opposition to the effects it has on its intended victims - you have your example in pre-war Germany, where many ignored the systematic attacks on the Jews - the result was inevitable.

"It is necessery only for a good man to do nothing for evil to triumph"
Edmund Burke

Calling somebody a bigot without backing it up with argument is a fairly sterile exercise, but even argument can have no effect on some people - I suggest that if anybody has any doubt of this, read through either the 'Dale Farm evictions', or the earlier 'Muslim prejudice' threads - baoth contain racism and bigotry in the extreme. Plenty of other examples on this forum, but these should keep you occupied.
Jim Carroll