Propaganda is just marketing. In fact, the guy who coined the word propaganda was an expert in marketing and advertising.
MAGAs have the Conservative Propaganda Machine, which is a wonder to behold, and 100% responsible for their success. They are extremely organized and have been honing their skills for DECADES. The CPM recruits, indoctrinates, excuses, rallies, insults, spins, and much more. It is their nuclear weapon, and they deploy it all day, EVERY day.
The Dems have literally nothing to offer in response. Even their own representatives, like Schmuck Schumer, are far more interested in insider trading than governing. He just recycles the same stern letter/speech for each loss of our Constitutional rights. Look at how Trump broadcasts his success with everything, even if it hasn't even happened. Contrast that with Biden, who had an extremely successful presidency, but the Dems didn't think it would be polite to brag. So his presidency ended up being dominated by his piss poor performance in reigning in MAGA, which was well within his rights and responsibilities to CRUSH as a viable National Security Threat, and he will forever be remembered as one of the weakest presidents in history.
If the Dems are ever going to regain power, they need to get control of their messaging. Right now, it is literally non-existent. It needs to be coordinated, widespread, and LOUD.
They also need a progressive platform, but that's a separate discussion.