Some of them are also “goldfish voters.” These people only engage with whatever political message has been delivered to them most recently. They literally can go from D to R and back again bumper sticker to bumper sticker.

Then there are the obligate ego independents. Their only political belief is that they must vote for both parties some of the time. If they voted D last time then they will probably vote R this time. Because their identity is “independent” so they must manifest that, all reason be damned.