The electoral math favors the Democrats big time today whereas in the 80's it favored the Republicans. So choosing the right candidate to run in 2016 is more important than ever. I do not think Cruz is that candidate. His favorable/unfavorable ratings is at 23% favorable, 31% unfavorable. With 46% of the electorate undecided Cruz could turn this around. But compare Cruz to Hillary in the favorable/unfavorable 49% ratings: 49% favorable, 45% unfavorable. But unlike Cruz, she has no wiggle room for improvement.
But back to the electoral math, Cruz is from Texas, a solid Republican state which almost any GOP candidate is going to carry.
Now Jeb Bush should be able to deliver Florida, a must win swing state for any Republican to have a chance of winning in 2016.
I do not think Curz could appeal to enough independents to do that in Florida. Another thing to remember, due to the large Democratic Party base, any Republican candidate must win approximately 55% of the independent vote. I do not see Cruz doing this either.