I read a study about the conservative mind v the Liberal mind. Conservatives make decisions based on emotion, with fear being the #1 motivator. And they are loyal to whomever they feel is going to 'protect' them. No matter if that person is harmful to others or not. For instance. The BULLY factor. They see a bully as strong and a protector. They don't see the bully as, well, a bully. Because the more 'followers' the bully has, the more the bully bullies, which attracts loyalty and devotion from their followers. And around and around they go. And the conservative mind is unchanging. To get them to change their minds is an act of strength. They are the ones who will do as a religion tells them to.
So, I think, the 'leaders', and certain News outlets, know this, and perpetuate fear. Notice the common talking points with the latest reports. ie; A former president's house was searched by the FBI. Now the pundits and 'news' casters, and even members of the republican party, have come out with the same 'talking points'. "if they can do this to a former president, they will do it to you". They don't take into consideration that the former president as committed atrocious acts against the country which in and of itself is unprecedented, they just see the person they are loyal to is being 'targeted'. However, to a rational mind, liberals, they see the manipulation tactics, and try to warn the followers, but because they have been manipulated emotionally for generations, they no longer trust anybody who goes against the person they are loyal too.
The Liberal mind is forward thinking, progressive, and scientific. However liberals, tend to constantly expect change, to where it gets them into trouble at times. Think of the die hard supporters of Jill Stein, and Ralph Nader. They will literally burn down the country if they don't get what they want and side with the opposition in retaliation. You cannot manipulate a liberal mind, because they basically ask too many questions and cast doubt on those who manipulate them. But give them a cause, ie; save the whales, donate to children in need, climate change, liberals are not stuck with an unchanging mind, but will exhaust themselves out trying to save the world.
So, I think, that is why 'grassroots' are successful with liberals. And the leaders of that party know that and promote grassroots ideals.
Then there are the Independents. I just started reading about independents. and basically they are the 'fence sitters', not that that is a bad thing, they are loyal to no one, they can change their minds, but if you pressure them they will turn against those who are pressuring them too. They have their causes, but it's limited, and they can be both scientific and religious, and they will often side with the conservatives based on their religious/scientific beliefs, but that's all I've read so far on them.