^The country is more polarized than you think. Her advantages with minorities and White women would still exist even without Trump and they made it very difficult for Kasich to win this race. As much as I hate to admit it, but the Clinton campaign would have turned him into Romney 2.0. Just because Trump is losing right now, that doesn't mean that any other Republican would be winning right now.
Voters are rejecting the Republican Party and conservatism, Trump is only making it worse.
No people are rejecting trump who is not a conservative. The fact is hillary would probably lose independents by 15-20 points vs kasich