The same is true the other way, If Cruz takes the nomination in a manner that causes 10 % of the 18 million Trump supporters to fail to vote (~1.8 million) and losses the 6 million he brought in, the republicans go from ~67 million votes to just around 60~61 million.
Unity ticket sure would be nice,
As I said, 2016 is a lost cause for the White House. I am focused now on saving at least one house of Congress to oppose Hillary. If Trump is the nominee, we most likely lose both the House and the Senate.