Republicans have suffered NO electoral consequences of this strategy. If it works consistently and has no negative side effects, why not embrace it? Don't tell me you still believe in our common decency or the validity of rational fact-based decision making.
I agree about 98% with your sentiments, but like I said in another thread, I think the Democrats could easily win without completely sinking to the morally bankrupt actions Republicans and Trump have sunk to. Here's an easy list that comes to mind:
1. Nominate a candidate with some charisma and without a bunch of negative baggage (whether or not that baggage is "deserved" does NOT matter at all). Clinton was a poor choice, even though she was eminently qualified. Obama had lots of charisma, Hillary Clinton almost none or maybe even negative charisma (such as her laugh that has been repeatedly used as a basis for insult and ridicule by her opponents).
2. Ditch the intellectual (and fair) arguments. Start with a simple (even stupid) slogan like Trump used that resonates with lots and lots of voters or potential voters. Make America Great Again -- Yay!! Just keep mentioning all the stuff voters care about, and for the love of God quit pandering to your "base."
3. Close to #2 above: Appeal to voters' basic wants and ditch all the complicated policy shit. Get in the dirt on the wedge issues, culture wars, etc. Tell voters you'll protect their Medicaid and social security and go after all those welfare cheats. You can honestly say those things knowing that there are very few actual welfare cheats, and meat-eating Red Staters eat that shit up. Tell voters you'll kick the Islamic State's ass, you'll be tough on North Korea and China and Russia and Iran. Who doesn't agree with that? Details hardly matter, so don't even bring them up.
4. Level lots of effective and even personal zingers at your opponent, particularly in the debates. They don't have to be disgusting insults like Trump used ("look at her face!"), just targeted attacks like the kind Reagan, Obama, and Lloyd "You're no Jack Kennedy" Bentsen have effectively delivered.