When Republicans named Donald Trump their candidate, the Democrats rubbed their hands with glee. They predicted that not only would Hillary Clinton win the presidency but Trump's election would also trigger a wave election that would give them control of both houses of Congress. It didn't happen. None of it did. Trump won and the Republicans kept control of both houses.
Donald Trump's victory over Hillary Clinton shouldn't have been a surprise. History was against Hillary Clinton. It's unusual for the same party to win three Presidential elections in a row. It's only happened once since FDR/Truman.
It's also uncommon for a candidate to win the general election after having trouble in the primary. Hillary's weakness as a candidate was obvious when she had problems against an aging socialist. Trump, by contrast, wrapped the primaries up months before Hillary did.
Most of the polls showed Hillary leading. She may yet win the popular vote although Trump has a 1% lead as of this writing. His margin of victory was razor-thin in multiple states. At least four states that had been predicted for Hillary flipped for Trump.
What happened?
The traditional wisdom is for a candidate to move to the right or left (depending on the party) in the primary and move to the center for the general election. Neither candidate did this. Trump mainly went with positive campaign ads while Hillary relied on a series of Trump quotes repackaged multiple ways. This probably cost her the election. She started these ads before the Republican primary when she was still running against Bernie Sanders. And punch they had wore off months ago. Finding a 22 year old tape of Trump discussing women added a couple of new quotes to the mix but Hillary never made a case for herself. Her strategy seemed to begin and end with making Trump the greater of two evils.
Narrative is everything in a presidential campaign. In 1992, her husband, Bill, was "the man from Hope" who felt people's pain. George W. Bush was a compassionate Republican. Obama made himself into a mythical creature. Trump promised to make America great again.
And Hillary? In her first campaign launch, she released a video of a bunch of women starting new projects. At the end she appeared announcing that she was a grandmother and she was going to run for president. It was so inspiring that she had to relaunch her campaign multiple times. She never did come up with a message. In a leaked email she complained that her staff had never created a message for her.
I'm sure that the Democrats will blame the FBI for Hillary's loss but that ignores the fact that it was her decision to have a private server in the first place. Was she hiding pay for play deals from FOIA requests or just keeping emails about yoga classes private? We may never know but without that decision, there would never have been anything for the FBI to investigate.
That was just one more piece of baggage dragging her down, along with Bill's treatment of women.
So, Hillary was a weak candidate with history against her and lots of baggage. That doesn't explain why the polls were wrong.
The pollsters made a lot of mistakes. Polls are based on models of expected voters. The models that most pollsters used were wrong. They overestimated the pro-Hillary turnout and underestimated the pro-Trump turnout. They also assumed that Hispanics would be solidly against Trump. While his numbers with Hispanics were worse than Bush's, they were better than McCain's or Romney's (or to put it differently, Obama did better with Hispanics than Hillary did).
It's also possible that Trump had closet supporters. Everyone on the Left from Hillary on down referred to Trump supporters as racist, sexist, xenophobes. Who's going to admit to that when a pollster calls?
I'm sure that the Democrats will also blame sexism - people being unwilling to vote for a woman. I'm sure that some people voted that way but Hillary got a boost from being a woman. Eight years in the Senate and four as Secretary of State does not make you the best qualified candidate ever. Hillary was only taken seriously because she was married to a former president - which does not qualify you for the office, either. (Note - George H. W. Bush was probably the best qualified candidate of my lifetime having been in the House, Chairman of the Republican Party, Ambassador to the UN, Envoy to China and Director of the CIA before becoming Vice-President.)
Money played an interesting role in the election. Hillary had a lot more money and was much better organized. But it wasn't enough to buy her an election. Most of Hillary's money came from the wealthy, too. Trump spent a fraction of what Hillary spent and a much higher percentage of his contributions came from small donors. This is ironic since Hillary included campaign finance reform in her platform.
One last thought - in winning the election, Trump defeated the two major political dynasties of the generation: the Bushes and the Clintons. In the 9 elections starting with 1980, only one didn't have a Bush or Clinton running for national office, either Vice-President or President. He dispatched Jeb Bush early on before running against Hillary.
Trump shouldn't be underestimated.