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In Iowa Trump is polling anywhere from 25 to 31% depending on who you ask. Doing math that Chizad can even nail the first time, that's roughly 3/4 of the people there that do not want trump. Since there are still 10 people in this race, 9 others are splitting that 70-75% hence putting trump in the de facto lead. Do you really think he would be in the lead if the bottom 6-7 dropped out? The head to head numbers between trump/Rubio and trump/Cruz with no one else factored in have Cruz and Rubio winning about 55-60% in each of those match ups with him. He is winning because people that have some sense are splitting their vote between 9 other people.
I kinda get the feeling that Trump will win Iowa, and the GOP field will narrow down to two or three as they realize he may actually win the nomination.
Trump, Bush, Cruz/Rubio. The other guys will bow out gracefully after being give some promises by the RNC.
There's no way the GOP can risk having Trump be their only hope. He's bullheaded enough to inspire the entire Democrat base to come out to vote against him.
If and when Hillary beats Bernie, I guarantee you the Left is going to have a Civil War. They will not be inspired and they will start questioning their identity. All the GOP has to do is produce a worthy candidate that can get people to the polls, and they should win.