There have been a total of 133 delegates allocated in Iowa, New Hampshire, South Carolina and Nevada to date. Trump has won 82 of them -- 61 percent. Ted Cruz is second with 17 delegates; Marco Rubio is third with 16. (FHQ's Josh Putnam has a terrific page that tracks the Republican delegate count.)
That early advantage is significant for this reason: Trump needs only 246 of the 624 delegates available on SEC/Super Tuesday to keep on pace to win the 1,237 delegates he needs to formally secure the Republican presidential nomination, according to calculations by Cook Political Report delegate expert David Wasserman. He writes:
Donald Trump is currently "on pace" to win 1,237 delegates after he claimed all 50 delegates in South Carolina on Saturday and 14 of Nevada's 30 delegates on Tuesday, pushing him up to 114 percent of his delegate target. The next closest contender, Marco Rubio, is at only 49 percent of his delegate target. Rubio and others don't have a lot of time to stop Trump: although only five percent of GOP delegates have been allocated so far, 65 percent of GOP delegates will be allocated by the end of March.
All of which makes Trump's task in the votes going forward far less daunting than the paths faced by the likes of Rubio and Cruz. Trump needs to win only 39 percent of the delegates available Tuesday, a showing that would amount to a drastic underperformance as compared to his success in the first four states. Overperform that 39 percent number, which seems likely given that he is tied or leading at the moment in virtually all of the states that vote March 1, and the delegate math for Trump gets even easier March 15 -- to the point that if he wins Ohio and Florida, winner-take-all states with large numbers of delegates, and Trump becomes the all-but-certain nominee.
The math is very much on Trump's side in the race going forward. Yes, the first four states are small and not terribly representative of the country as a whole. But Trump's overperformance in them has put him on what could well turn into a glide path for the nomination come Tuesday night.