How did Reagan contribute to the mess we are in, over 20 years ago?
He was a massive proponent of deregulation which started the unraveling of the yarn, if you will. He made deregulation and ideological theme. In order to do this he needed plausible support from the people whom the regulation was ultimately intended to protect. He used a variety of bumper sticker type slogans like “getting the government off our backs.” He created theatrical hypothetical villains and was celebrated for titling his lance at these windmills. He mixed this in with cutting taxes to create enough populist appeal to undertake the removal of many restrictions imposed by government. Thomas Frank explored this phenomenon in more recent years in a book called “What’s the Matter with Kansas.”
Bill Clinton took it even further where Reagan didn't have the balls to go. So it's not like there's one side to the story, there's been a rolling push for government deregulation over the past 20 years through multiple administrations which caused massive imbalances in the markets, created monopolies (Clear Channel gobbling up every media outlet it could controlling the air waves) and eventually allowing sub prime mortgages which were a heavy contributor to the collapse (amongst other things).
That's why I find it so amusing when people outright defend democrats or republicans. There's no such thing. People should be loyal to the ideals of the party, not the party itself. Just take a look at history, when it comes to the important things, the issues that shape our nation, it doesn't matter what side they are on.