Romney has more than twice as many delegates as Santorum, who has more than twice as many as Gingrich, who has more than twice as many as Paul. Romney is just 8 delegates shy of halfway to an 1144 majority. He has more delegates than the other three guys combined, 568 vs. 458.
On the other hand, when you look at how many votes each has received, the spread is tighter. RealClearPolitics reports the following numbers: Romney 4,127,915; Santorum 2,850,541; Gingrich 2,212,001; and Paul 1,079,751.
Romney has 55% of the delegates, but has only gotten roughly 40% of the votes cast. It's the 60% voting "other-than-Romney" that encourages Rick and Newt and keeps them in the race. Ron Paul as a spokesperson of the libertarian cause seems not to care a lot about winning.
