To be honest the Democratic primary process is flawed. The republicans pick their nominee based upon the general election model; if you win the state you win all of the delegates. There are no caucauses and there is no division based upon districts.
Anyone who wins California, Texas, NY, FL, Ohio, and Pennsylvania is 100% guranteed the nomination. She is hanging on because she won these states and is marginally behind in delegates and popular votes. I gurantee your *** woudn't quit if you were that close and you had $180 million + worth of funds raised. You'd work your little couchie off to make the strongest showing possible.