Democrats, take a few days to get the angst out of your system, and then be sure it's out. The time is now to go to work for 2018 and to resist whatever legislation put forward that conflicts with your values. Hard work lies ahead of you, but if you roll over and play dead because of despair, you make things worse.
However, this does not mean opposition merely for the sake of opposition. Our country has seen too much of that already. Be constructive whenever possible. Not every idea put forward by Trump will be bad.
Practical effort is better than despair. Politics is very rough, even when the elections are not so negative. You win some, you lose some. It's the cyclical nature of politics. You got beat this time. Listen to the voters, learn from the loss, and move on.
Bear in mind that Hillary Clinton was always a vulnerable candidate. Proof? Barack Obama came from seemingly nowhere in 2008 to grab the nomination from her. More proof? She had a very difficult time this year putting away her opponent Bernie Sanders, who was probably farther to the left than any presidential aspirant in the last 100 years. The "email thing" eroded trust in her, as did the poorly executed push in 1994 for national healthcare that first gave Republicans control of the U.S. House. Ironically, Colin Powell (no fan of Trump!) had warned that "Everything HRC touches she kind of screws up with hubris." If she had just come clean with the American people years ago and admitted that she made a mistake with the emails — despite the fact that others made the same mistake — she might have been able to put the mess behind her. But she didn't, in the same way that Bill Clinton defended his unethical behavior with Monica Lewinsky. I think how it's how they think. Hubris.
Going into the next election, do not believe any poll unless it shows a margin of 55-45 or more. Otherwise you get false hopes that are too easily deflated. Polls have become notoriously unreliable.
Most importantly, don't indiscriminately demonize everyone who voted for Trump. I have family members (extended family) who voted for Trump. They aren't racist, although their political views differ greatly from mine. If you demonize everyone who voted for Trump, not only do you contribute to more poisonous rhetoric, you do unto them exactly what you say they do unto others.
Some number of people voted for Trump because they're dissatisfied with the economy. Take a trip through rural North Carolina and you could easily understand why. Yes, the economy is far better in Raleigh (for example) today than in 2008, but that's not the case in Hoke County. Some voters were particularly irate about the impact of free trade, which in general Bill Clinton supported. Ross Perot's "giant sucking sound" is still ringing in the ears of many Americans, and our federal government has not done enough to help those citizens. They're mad as hell and I hear them.