"They need both Jeb and Rubio alive in Florida. They
need Cruz to remain Option B to delay the
establishment swallowing their pride. They need
Rubio not to be a clear Option C until they are past
Florida," observes a plugged-in Washington lobbyist
who is anti-Trump...."
http://www.usnews.com/news/blogs/run-2016/2016/02/16/why-donald-trump-needs-jeb-bush-to-do-well