have so many more delegates than the Republicans (like 2 to 1)?
I don't know why but this has always been the case since at least the Primary process was opened up for the 1972 Presidential election, so if you want to find out the reason you probably have to go back to when the rules were being rewritten for the Democratic Party Presidential nomination process by George McGovern and his fellow commissioners following the 1968 convention. At one time there were even half delegates which I first heard about in 1984 at the age of 13 and that concept totally confused me at the time and brought up images from horror movies.
Half delegates were a thing for over a hundred years. It let state parties reward more loyalists, and to pack the convention hall. They've been disappearing pretty steadily over the last few decades - on the Dem side only Dems Abroad awarded half delegates this cycle.
