1) The most interesting thing that happened was how well marijuana did at the ballot (2 states and DC legalizing it entirely and Florida's medical marijuana vote going extremely well, 58%, but not passing). And how poorly anti-abortion or how well minimum wages did as issues. I'm not a fan of minimum wage laws, in that I don't think they're an effective way to address income inequality. Nor do I care if people work at companies full-time and yet still qualify for various social welfare programmes. I think that's actually a net good even though I think the social welfare programmes are inefficiently scaled (and can cause heavy disincentives at the margin), simply because it is more tolerable to almost everyone that we provide social welfare to people who are working (or can't work) but aren't making ends meet at the margins. However, those complicated economic objections aside. The fact that many people do seem to think min wage is somehow effective at helping poor people suggests that many people voting for increases in it were concerned about income distribution or the general economy. Mostly what happened is a lot of liberal-ish sounding things passed but a lot of conservatives won elections. I thought that was very odd.
2) Conservatives did not score as many own goals as they have the last few cycles. Democrats did. The one case that eludes me is how a Congressman with 20 indictments for various forms of corruption can win re-election. That seems like it ought to be a pretty damning own goal problem. Apparently saying dumb things about female anatomy is (and it ought to be pretty damning), as is sending photographs of your own anatomy (if male, this is stupid but doesn't strike me as potentially damning politically), but potentially violating the law is not. Good to know.
3) It is not enough to tell people what your opponent might do that is terrible. You need to have something to sell yourself on. In Colorado, Udall's campaign was running a ton of negative ads relating to an opponent's prior support for strong anti-abortion laws. These apparently turned voters off rather than working as a scare tactic. Meanwhile, Udall's actual record included being a staunch anti-NSA reformer by rhetoric and voting and even opposing expansive foreign policy conduct (by his own party's President). Those may not be broadly popular everywhere, but I'd have to think they could have been popular in Colorado. Various media outlets subsequently endorsed his rival simply because they were so annoyed with the negative portrayals instead of the salesmanship of what he could offer.
This strategy is especially poor at working on liberals and motivating them to vote in large numbers. Fear is a conservative weapon, and they're very good at using it. Liberals also need something to escape their fear with, which they're not as good at using lately. It's possible that Republicans will spend a lot of time trying to kill judicial appointments, overturn or at least sabotage Obamacare, or trying to bring up impeachment and investigations of the Obama administration. But. I think if they want to win in 2016, they won't be able to do that. They need to try to govern in order to not be punished by the general disdain for Republicans (both parties really, but they're especially unpopular) and their best option is to try to pass laws to show what their agenda is and then have Obama veto them or the Senate filibustering them if they're particularly egregious. So talking about these things as fears isn't really that practical because they're more vague and unlikely to be realized as actual problems. Specific policies like anti-abortion laws or attacks on birth control accessibility might be more plausible, but it would still be better still to actually defend birth control accessibility as a thing, or access to abortion rather than simply oppose those who don't want them. They can stand on their own with or without pointing out that someone hates it.
4) Lots of people who voted clearly do not pay attention to politics. While I found the photo bomb on McConnell in Kentucky hilarious, it was pretty obvious a couple months ago he was going to win that race and win it comfortably. It was called almost immediately because it was clearly won months ago. The question mark was the margin, which was higher than polls suggested. That was an ominous sign that portended several other defeats, including some unexpected governorships. Kasich as governor was in a similar boat as that race was settled months ago (and won by an even more comfortable margin as Fitzgerald was one of the "own goal" Democrats). People who don't pay attention to these horse races and just show up to vote don't really have valid complaints to make and their surprise is particularly off-putting as pathetic. What people should be doing is spending some of the time ahead of the elections trying to make the argument against McConnell or Kasich or for their candidate of preference in some conversation with other human beings. This rather quickly establishes how strong a candidacy is even without referencing polling data as you'd know immediately there's a ton of people around who don't share your views and may need to be talked to or argued with or that you live in a bubble of people who agree with you and need to talk to a few strangers for sampling purposes. Instead of showing up on election day and suddenly being surprised there's legions of people who voted for the other guy and calling it a day. There is no actual prohibition against talking about politics and policy matters. Most people just don't like fighting over it because they're usually ill-informed and think they aren't.
5) Something I think liberals don't often realize, and this goes back to the fear element: Politics is not about policy. It's about tribalism. Getting your tribe to stand up and shout down the other one. Sometimes it's about finding some other tribe (in another land) to unify against and shout down. Sometimes it's about picking fights within your own tribe. Mostly it's about shouting at other tribes though. It is not about ideology. It is not about political policy positions. Almost no one pays that much attention to know what those even are. Liberals, or to some extent moderates, and that rare band of independents, do care about those things. Some conservatives care about a few particular policies. But people, and especially conservatives, mostly care whether they are in charge of setting those policies and getting to lord that over their foes. As do many "liberal" political figures (Obama included). It isn't a contest about who has better arguments, who can debate the particulars of policy concerns and constraints, or even who looks better on TV. It's a contest about who gets to do things and try to brag about it and who gets to not do things and complain about what is being done.