Running as the inevitable nominee, then inevitable President because it was your turn didn't work for Hillary in '08. Until some dirty tricks within the DNC, it might not have worked in '16 either. Team HRC would have been smart to let the nomination race conclude organically (without institutional interference). The folks who Bernie Sanders brought in from the outside, returned to the outside after he was ousted from the contest. Who's to say, but if he lost to her in a fair and transparent way, those folks could have been the extra 4-5pts that would see her with a 370+ electoral vote win instead of losing to Donald Trump.
Economic voters are still economic voters. Obama campaigned on the economy in '08 and won. Again in '12 as the economy was finally growing again.
Well pocket book issues still matter, and Trump, for all of his flaws, had an economic message. It doesn't mean it will work; pledging massive tax cuts that typically benefits the 1% are still a politically sexy thing to offer. And when you're dealing with a voter base that traditionally doesn't trust government, offering to out some more coins in their pockets gets their attention.
Trump is a womanizing dirtbag. So was Bill Clinton. The two are not comparable, and Bill wasn't on the ballot, but there was a little political genius in attacking him. The very folks that supported and kept Bill Clinton in office didn't care about his personal flaws, and both Hillary and Bill counted on that. But now, she was counting on those same folks to judge as unfit, Donald Trump, after proving that voters don't give a crap about that. Trump figured this out and used Bill as his own defense. It worked.
The open support of white supremacists (or, if you prefer the more sanitized "Alt-right" crowd) failed to dissuade folks from voting Trump because his campaign latched on to a popular (but wrong) myth that immigrants were taking American jobs. More accurately, Republican attacks on education were making Americans fall further behind and less competitive in the global economy while the country simultaneously needing to hire for a growing high tech sector. That argument wasn't being made though; it seemed as though by simply only condemning the KKK links to the Trump campaign the Democrats ignored a false theory on immigrants/jobs. End result, "immigrants taking our jobs" argument was left to stand as 'fact', and worse, went a great distance to partly rehabilitate the Klan as a legitimate political influence in American politics.
Gender had little to do with this. Several states have voted for strong conservative women as Republican Senators, Governors, state level representatives and such. Having said that, clearly there will be some who'd never vote for a woman for President. Those people exist. But remember this: the folks who some on the left would dismiss as anti-woman voters forget that conservative Republican Sarah Palin was on the Presidential ticket in '08 and received almost the same 60 million votes as Trump did in '16.
It wasn't gender. It was Hillary Clinton that some had issues with.
Thus concludes an absolute disaster of American politics for another cycle. Donald Trump will be the 45th President as he won the election and now has the right to serve as such. I have little doubt that he will be a disaster for America. And that will be the Democrats opportunity if they're smart. Give voters something to vote for, not another contest of who's less bad than the other.
I haven't even addressed the many other policy flaws that Hillary has, and there are many. Her support of Bush's war in Iraq, her support of the Patriot Act, her uncomfortably close links to big banks, big oil to name a couple; and put her strangely close to some Republicans that she'd pretend to oppose.
You can't campaign as something different while offering little difference in policy. Obama did, and he captured the imagination of a generation. That wave in '08 swept away Republicans at all levels. Democrats kept the house, expanded their hold in the Senate. Obama offered folks something different and delivered. Hillary didn't..but Trump did. That's why she lost.
That's my take.