Trump ran a smarter campaign

Mark McKinnon:

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Even when I was in charge of advertising for the George W. Bush campaigns in 2000 and 2004, I thought a lot of money spent on TV ads was wasted. And argued the campaign should think about other ways to spend the money. Donald Trump got that. And took it to an extreme. He spent more money on hats than ads or field organization, which seemed crazy at the time. But in retrospect, they were obviously better investments.

All the research when averaged out over the campaign had Hillary Clinton ahead the whole campaign. President Obama’s smartest strategist predicted there was 100 percent chance Clinton would win. 100 percent! Which fogged everyone’s lenses, including mine.

It seems likely that when it came to polling, Trump supporters participated in a “spiral of silence.” They don’t trust the establishment. Or the media. Why would they trust or talk to pollsters? Or acknowledge their support publicly only to be called ignorant, uneducated, misogynist, or racist? I think it’s more than likely they either didn’t respond to pollsters or intentionally misled them.

And Clinton was very well known and running for a third term for Democrats, so was effectively the incumbent. It should have been a clear warning sign when she never really polled above about 43 percent, because under this scenario, undecided voters are almost always going to break to the challenger.
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At the very first Trump rally I attended a year ago, and at the last rally I attended the day before the election, I was blown away. They were combination rock concert and church revival. I’ve never seen anything like them in more than three decades of working in politics. People got off work in the middle of day and stood in lines for hours in the blazing heat and freezing cold. They were passionate, enthusiastic, and totally dedicated.

Trump voters were never going anywhere else. No matter what they heard from the media or other candidates, they were sticking with their guy. In fact, all the attacks just hardened their resolve....
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There is much more.

The Hillary Clinton campaign lacked excitement.  Sometimes her VP running mate attracted only a handful of people to his stops.  She seemed to take her "victory" for granted while she and most of the media missed what was happening in the Trump campaign because they believed what the media was saying about him rather than what his crowds said about the passion he had stirred.