Why are the democrats losing so much?

Reading this article on why the democrats are losing, I can tell that the author is a bit more socially left-wing than I am, but I agree with his points on why the democrats are losing elections (and influence) at breakneck speed.

You can't attack the single largest group of voters on a constant basis and expect them to vote for you. Calling people racist, sexist, bigots, deplorable, bitter Bible clingers and evil gun nuts is going to make them hate you and they will not vote for you. If you label them "irredeemable", just as Hillary Clinton did, then they figure they have nothing to lose by voting for a guy for no other reason than to poke a stick in your eye.

You can't focus solely on issues that MIGHT affect a minuscule fraction of the population and ignore the issues that are guaranteed to touch every single person and then expect to win.

If attacking gun rights has cost your party nearly a thousand nationwide legislature seats and several governors, and now the White House, then why would you continue to do so?

The democrats have convinced themselves that the left is the majority in America. Many of us have always felt like this is untrue. Ignoring the true philosophical majority (middle-right conservatives) in America doesn't actually cause that majority to disappear. That majority has finally shed the idea that because they are the minority (they aren't) that it means they are wasting their time by even showing up to the polls. They have shown up for the last few elections, including the most recent general election, and they delivered a stern message to the left.

I personally hope that the democrats and the left do NOT heed the advice in article (top link) or the points in my post here. While I do not want to see a single party government running things, we have no need for a far-left, Liberty-hating party like the Democratic Party. The author of the article suggests that he'd like to see the libertarian party replace the democrats. As unlikely as that is, America would benefit greatly if we had the R's and the L's competing for Congressional seats instead of the R's and D's. It could result in the two parties actively trying to out-Liberty each other to get your votes, kind of like when businesses compete for your patronage.

Wouldn't that be nice?