Democrats have become the corporate party
Pharamaceutical corporations, as an example, used to be like banks where they would donate and try to control both sides, although they seemed to favor Republicans because Republicans pushed for strict regulation of things like intelectual property and imports to keep down competition. But now, the bias hasn't just reversed, it's swung as far left as possible. These companies donate exclusively to Democrats now. The love the prospects of socialization, more free drugs for more people, at exorbitant prices charged to the public. Obamacare sent insurance stocks up 1000% for the big players. It was insane. Big Pharma has become bigger than Big Oil.
To see what's going on with voters within the parties, take an issue like vaccination. It used to be supported by everyone, except a few liberal hippies who believed in magic healing powers of dirt, and didn't like giving money to corporations. It was the deep red states like Alabama and West Virginia who were first to mandate vaccination and eliminate exemptions. But now it's the other way around. Now it's conservatives who are the ones saying they don't trust the authorities, the fascist merger of corporation and state as embodied by CDC scientists, and their revolving door between the public and private sector. Conservatives have good reason to be distrustful. Liberals had been insisting for years that corporations care about their bottom line and not your health. What happened? Now it's liberals in California who have mandated vaccines and outlawed exemptions, liberals who insist we are anti-science if we don't trust them, liberals who want a war on whistleblowers and alternative media.
This is more than a reversal. This is a total realignment.