Why will the US try to have a relationship with Communist China, but not Communist Cuba?

Two reasons. First is that China is a huge trading partner, and it would not be economically viable to isolate them. Second is that there is no large voting block of Chinese nationals who think they will get their nationalized property returned to them if the current Chinese government is overthrown in a state with a large number of electoral votes.

I think it has to do with precedent. At one point US politicians believed that an embargo was the best way to deal with Soviet Communist aggression and expansion in relation to Cuba. At that point in time, that decision may have been the best course of action. As things changed, subsequent leaders did not want to alter this precedent. Especially as the same leader, Castro, was still in power. I think the best stance would be to take a more open policy toward Cuba, and more restrictive stance with China, not because of they are commies but because of their labor abuses in the products they manufacture and send to the US. But economics also play a part and China is potentially a much larger market than Cuba.

Because China owns us. The US owes them quite a chunk of money. We import a lot of cheap manufactured goods from China. If we pissed off China it would seriously screw up our own economy. They are too important to challenge.

Cuba basically has nothing we want besides cigars, rum, some nice beaches and great music. Fidel Castro is known for being very anti-American in his speeches and propaganda. Now it's his brother in power so maybe this guy will be more open to talks. Who knows?

China carries some of our dept. recently they even bought market value fannie mae and fannie mac stock. China represents value to our manufacturer base to make goods at cheaper wages that an American cannot afford to take, China also is a security council member.

Cuba is an country the U.S. wants to forget about since it has basically stood up to our economic embargos, but most because SouthAmerican countries still consider Cuba one of their own.

Americans owe so much money to china they owe money to cuba also but they owe the most amount of money to china.

Oddly many politicians and wealthy go through Canada to go to Cuba,now they will have to stop since they are putting metal chips in passports to learn whereabout s of citizens from here

Its all about moeny or pleasure other wise its all show

Money.

China has the second largest un-tapped market whereas Cuba has... er.. well ... iguana ?

One word: MONEY.