I'm curious to see where you obtained your "80%" figures. The typical number I've heard is 60%, but those are based on phone polls, and in a country with 12 phone lines per 100 citizens, that isn't very representative, ESPECIALLY among his primary support base (for a total of 7.2% of the population surveyed - if my math is right). Chavez is hugely popular among the poor in Venezuela. It is the middle-class and upper-class business owners that want him out. They were the ones behind the strike in 2002-2003 and they are the ones protesting now. The poor see him as a hero; someone who represents them. He has already agreed to a recall election, but based on the above statistics, it's likely that he will win again, which is a very likely reason dissenters are trying to incite a coup. There's also been a lot of talk surrounding US involvement in the last attempted coup and in this recent protest, and based on past US involvement in Latin American polictics, there's a pretty good chance they are more than rumors. So, if these parties were backed by, say, the CIA, of course they would be calling for more US involvement. Latin American politics are much more than they seem. The US has had their fingers in them for a long time.
And can we please stop throwing around the "terrorist" moniker and applying it to anyone who doesn't have the same political ideals as the party in office? It really gets old.