Yes, the International Worker's Day should be recognized by the USA.
No, May Day is a conspiracy from godless communists.
Its not exactly the fact that socialism is bad, but more along the lines that America has bad experience with it. To understand why are culture is so extremely capitalist, you have to realize it results from a long cold war and red terror period in the US. Americans were always in fear of nuclear war, and that morphed into anti socialist slairs. The democratic party is having enough trouble getting people to accept more social control, and recognizing this holiday is to volatile.
As a communist, even I think it would be insanity to go around America of all places celebrating May Day. The ultra-conservatives would have a huge hissy-fit about it.
May Day is a pagan fertility celebration. So, May day has to come BEFORE "labor day". It's biology