Why did America's Style of a Constitutional Republic not catch on with the rest of the world the way Communism did?

Many of the ideas of the American Revolution are not American in origin, but came from enlightenment thinkers of the French Revolution. America was always isolated from Europe and the rest of the world and not influenced by them as much. Prior to WWII, America mostly stayed out of global affairs and did not export its ideas.

That Depends. Communism as a global movement is constantly agitating unrest and discord. Maybe that's the reason.

There is an accurate twofold answer to your question. First of all, in the vast majority of Third World countries, the value of a human life is even less than that of a Chicken, or a Goat. The ideals of PEOPLE voting for their rulers wasn't broadcast very widely, and repudiated when it was. I am old enough to remember Nikita Kruschev, sitting at his desk in a meeting of the United Nations. Glaring at the American Ambassador to the U.N., and banging his shoe, repeatedly, on the top of his desk, Kruschev screamed, over, and over again, " We will bury you! We will bury you!" And, this leads me to my second answer to your question. You see, Socialists hope you are stupid enough to actually VOTE them into power. The Communists didn't give a damn WHAT you wanted.....They took over countries with military force. They ruled people with military force. No one " voted " Communists INTO power, and no one DARED to " vote them OUT of power.

Because Marxism sounds better. It sounds great, everyone being completely equal, getting everything free. But eventually people realized that it's a horrible system

Only Americans think that America's government is the best in the world. Everybody else thinks their 2-party system is insane.