2) many/most primary voters have very weak allegiance to any particular candidate, can be influenced by party actors into not voting for someone they think is toxic, because of #1, 3) the field will be winnowed, and Trump's favorability #s and name recognition suggest that he has less room for growth than the others, once people start dropping out,
http://www.bloombergview.com/articles/2015-07-30/no-trump-can-t-win-yes-clinton-can-
Read that Bernstein article and the NYT article linked within on how party actors herd voters to their preferred candidates. Here's the key paragraph on the dynamics.
First of all, polling does play a role in the dynamics as outlined here so it's inconsistent to use that to support an argument that polling doesn't matter. Except to argue it doesn't matter until party actors start attempting to influence it I suppose, but they already are and not especially effectively. News of Bush's dominance in fundraising hasn't surged him into the lead.
I think one of the problems with using past cycles for analysis is that campaign finance, how voters consume news and wider attitudes about party leaders have changed rapidly. Even 8 years ago, Giuliani had attracted more donors and built higher polling than McCain who slayed him. And things have continued to change dramatically since then. With donation limits effectively repealed by the SC and Super PACs and a handful of mega-donors able to level the playing field, we see Ted Cruz outraising everyone except Bush, but enough to compete with Bush. That's a huge difference from most past candidates despised by party leaders. After Gingrich won South Carolina and surged into the lead in Florida (despite party leaders rallying to Romney against Gingrich), Romney drowned him in vicious ads, outspending him 5:1. Trump is his own mega-donor and, if he's willing to spend, can match Bush for example.
I'd also say the ability of endorsements to influence voters may be weaker. The Republican Party methodically marshaled every prominent person to pounce on Trump after his attack on McCain, join the consensus that his comments disqualify him and he should probably step aside and his polling lead grows. Guys like Tom Coburn come out for Rubio who plummets.
And primary voters are also much more fragmented on how they consume their news than they were in the last decades of the 20th Century. Breitbart and FOX News have more sway.
I'm still skeptical Trump will win a primary because he's a crazy person who can say anything at any given moment. But I think party leaders' influence has likely waned. Or, put another way, they've frayed and some strands are pulling pariah candidates.
Poll
