By saying income inequality is the worst thing we are facing its ideological left lean is pretty obvious. There are a ton of books written from the left to try to puncture holes in the market and make the case for more state involvement.
I didn't respond to this earlier because it's not that big a deal to me and if Vanguard wants to claim that income inequality is only considered a problem or 'the worst thing' from the ideological left, I didn't agree with it, but I wasn't going to argue the point.
However, I always planned to respond if an article came along that I saw and one has:
http://www.businessinsider.com/inequality-impact-economic-growth-2017-9?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+TheMoneyGame+%28The+Money+Game%29"Inequality is getting so bad it's threatening the very foundation of economic growth"
That income inequality can impede economic growth and is a serious and growing problem is not just a view from the 'ideological left' but is held by those on the left, center and the center right. Only the loony libertarians with their goofy Austrian School Economics completely dismiss concerns over rising income inequality.