“the Democrats have moved radically to the left and are now support positions that in the past would have been considered off-the wall radical”
Actually it is far more complicated.
The Democratic party has moved to the Left because it made things uncomfortable for southern racists like Strom Thurmond, Jesse Helms, Mills Godwin and their ilk. They became Republicans and the Republican party (most of it, at least) welcomed them with open arms as part of Nixon’s “southern strategy” which represented a horrible immoral political opportunism. (I have seen videos of Nixon in the 1960 campaign calling for more civil rights laws!) And at the same time reasonable southern Republicans like Linwood Holton were forced out. (Holton eventually supported Barack Obama for President and his son in law is now a Democratic US Senator).
However, outside of the South, the Democratic party is far more conservative today than 50 years ago. For example, it was normative for northern Democrats to support single payer universal health insurance for everyone, not just the elderly. Democrats not usually associated with the Left such as John Dingell and Henry Jackson were big supporters! Huge fractions of northern Democrats wanted to decimate the US Defense Department budget; now it is only Libertarians like Gary Johnson who express such ideas. (Bernie Sanders even supports the F-35, which his own foreign policy advisor Bill French correctly calls a massive boondoggle!) I am aware of no Democrat of importance today who wants to return tax rates to Eisenhower levels when the US experienced great prosperity; the sluggish growth in median incomes began with the Reagan tax cuts!
By European standards the Democratic Party in the US would be called a “center right” party. The Likud Party in Israel is more to the Left!