fear - legitimate tactic?

I think that while fear is a useful tactic in some campaigns, it should not be an accepted means of campaigning. In any case, it should be limited. There are several examples of times that fear worked for a candidate to win a campaign, as well as many that show that it did not work. One example of a fear campaign working was in 1964, when Lyndon Johnson won by saying that Barry Goldwater would blow up the world. One example of it not working is when Jimmy Carter was unable to win over Ronald Reagan in 1980. Carter was trying to say how Reagan was "out of the mainstream". Now, fear is being used in this campaign as well. It is a known thing that Barack Obama has ties to terrorist groups. Whether or not this knowledge will be useful for getting people not to vote for Obama becoming President will become apparent in the upcoming elections.