"MAGA" technically means "make America great again." Liberals have never really understood what "MAGA" really represents to people, why it appeals to so many, and as a result they've never been able to counteract its effect. Democrats and liberals have spent years trying to define "MAGA" on their own terms. And what they don't ever seem to realize is that they're playing right into the MAGA strategy, creating more MAGA folks and reinforcing the MAGA appeal those who already have bought in.
So let's see if I can help Democrats have a breakthrough.
MAGA is a vague idea. It's amorphous. No, it doesn't mean whatever someone wants it to mean. It means whatever someone needs it to mean. MAGA is one simple thing: the affirmation of nostalgia.
Everyone is nostalgic at times. Everyone has happy memories of a different time. Everyone looks back fondly at something. Even if you've had the best, most amazing life possible, there will still be room for nostalgia. But the thing is, not all nostalgia is about what you did. Sometimes nostalgia is what you thought. It can be something you saw. It can even be something you thought you saw, and then longed for, from a very long time ago.
Democrats have been keen to say that "MAGA" people are nostalgic for white supremacy, Jim Crow, and things like that. In other words, Democrats keep trying to define MAGA on Democrats own terms. The Democrats have largely adopted an identity politics world view, so they can only perceive MAGA as an expression of identity politics. This is why when a black person buys into MAGA, that person is accused of being an Uncle Tom. But every time Democrats do this, they can't seem to figure out that all they're doing with this rhetoric is inflaming other people's nostalgia for a time before the identity politics took hold.
MAGA is nostalgia. But not for anything specific. MAGA enables people to be nostalgic about whatever you want. Maybe you have a nostalgic memory of being a kid in the mid 80s, about 5 or 6 years old, twisting the channel knob on the TV after Sesame Street just ended, and Lifestyles of the Rich and the Famous comes on. There's Donald, doing rich people stuff. You're playing with your Barbies and fantasizing about champagne wishes and caviar dreams, whatever that means as Mommy walks in with a PBJ sandwich with the crust cut off (a daily ritual). As you reminisce about those times, you happen to glance over at your own 5 year old daughter, playing with her tablet on a Saturday afternoon. And as you hand her a freshly unwrapped Uncrustable (a mere weekend ritual), it occurs to you that things are just different now. Your own childhood was somehow much more wholesome. It was a simpler time. It was more direct. It was real. You wonder how you're going to raise your own daughter to really feel something out of this life. Whatever else may have been wrong with the world, you got here, and you're a good person. And as the Democrats keep telling you, the world is a chaotic, awful place, full of terrible people.
And that is when it starts to set in. It's all a very personal experience.
Democrats need to realize that the more they tell others what MAGA means, the more they sound like idiots. Because you can't tell people what to feel when they remember their own younger life fondly. You can't demand what facts have to be inserted to other person's memories. You can't tell other people that their life was wrong all those years ago.
When people hear "make America great again" the greatness they envision is their own, personal life. And that is why anything Democrats try to associate MAGA with can be so easily ignored by adherents. That's why they can ignore so many of the things they witness that they don't like. Because MAGA is relative. Adherents understand MAGA as being relative to themselves, in their own terms, not yours.
You can't neutralize MAGA, like baking soda neutralizing acid. You have to supersede it. If Democrats can't do that, then they'll be losing to MAGA for decades yet to come.
Think the voters will buy it? 
