The article gives two ranges: 1947-1979, 1980-Present. Reagan's presidency (1981-1989), and the political changes it brought, coincided with the beginning of the second range.
Right, again, I think there's a political dimension to this, but I don't think Reagan created the problems two years before he got into office. My gut tells me economic repercussions like this probably lag their causes by several years, and looking at the graph, there's reason to think the problem started even earlier in the seventies.
In short, saying Reagan had a big part in this is a claim I would support, but saying it's all Reagan's fault is clearly untrue, barring time travel.
In short, saying Reagan had a big part in this is a claim I would support, but saying it's all Reagan's fault is clearly untrue, barring time travel.