<strong><em>Jonathan Nack</em> reports from Havana: </strong> Hundreds of thousands of Cubans demonstrated unmistakeable enthusiasm while marching in the Cuban capitol on May Day - International Workers Day. Marchers chanted, danced, sang songs, and blew horns throughout the festive march. It was a clear statement of support for the Cuban government. CBS News reported an estimated 600,000 participated. Trade unionists, community groups, members of cooperatives, and even unions of small businesses demonstrated their support for the Cuban Revolution.