If it's grandstanding to try resolve an issue without entirely submitting to the pathetic tactics of a party who will only accept a Scalia clone, then you've lost me there.
He should have went with a moderate Republican (think a Justice Kennedy type). Garld is a moderate Democrat who was appointed to his current position by Bill Clinton.
To being the topic back to the election itself, what is notable here is the both parties have a long nomination fights on their hands. Bernie Sanders, while the underdog, has put up enough of a fight against Hillary that she cannot afford to alienate his supporters come general election time. While they wouldn't vote for Trump, many might stay home or vote for a liberal third party like the Greens.
Trump will be the nominee, though Cruz may drag it out alll the way until June. If Cruz's strategy is to win enough delegates to cause a brokered convention, his problem is pretty much all the states going forward as winner-take-all either outright or by congressional district. We're done with the proportional states. That means a good 2nd place margin doesn't matter anymore. He has to actually win and win a lot.
I think the general election will be close. The flaws that are keeping Hillary from running away with the primaries won't go away come general election time. Trade was the issue that caused Sanders an upset win in Michigan and has been keeping Midwest primaries close. Him and Trump are similar on trade issues, so he could tap into those frustrations in key states like Ohio.