“He should be thanking the system that gives him 22% more delegates in proportion to the individual voting”
*****
And thanking Rubio and Carson for staying in the race as long as they did so it made it easier to win, particularly in states that allowed Dimwit/Induhpendent votes in GOP primaries.
Pennsylvania is a closed primary, but we've had, at last count, over 100,000 net voters switch to GOP registration to vote for Trump, judging by his huge lead in the polls here.
I'd wager that Trump is a net beneficiary of crossover voting. How many of those will stick with him in November remain to be seen.