"The difference is that liberals [like Sanders] want to come home because they think we are not good enough for the world." I would rather say, in nearly ever conflict, the disagreements which are usually civil wars, are not worth the death of our troops. 
While Trump tries to regain some respect among the vast majority who fear his election, Cruz flails helplessly sinking deeper as he acts desperate, inviting a running-mate who once said Cruz will "say whatever he needs to say to get elected." 
Maybe the election process is working just as it should. The Republican establishment anointed Jeb Bush who was a failure with voters. Trump clicked with the largest percentage of voters, and now he's the likely nominee.
Sanders also made a tough race for the presumed nominee, Clinton, who likely won in part because independents could not vote in many contests and older women want to see the first woman president.
Trump will cause a seismic shift in Congress to the left. Elections work.