Ah, pan-national trends, always a fun way for everybody to get pseudoscientific, yo.
There's a pretty clear trend of populism rising throughout the west that's being fueled by both macroeconomic and cultural trends. Though this populism definitely isn't exclusive to the left or right as OP is suggesting.
I think the idea of "populism" is increasingly becoming stretched to a point of outright absurdity. By definition, if you're winning an actual election you're going to have some populist appeal. Nobody has ever won an election without it, and anybody that claims to never use any populist ideas (and still has above ten percent of the vote) is a fat liar. If the definition is merely insurgent parties and odd individuals surging, well that's a bit better but it's still a bit wonky if you actually start breaking the list down again (to the point you could probably make a decent case for THE POPULIST EXPLOSION in various other points in postwar history, and you could quibble that about half the options are seeing their insurgents are waning somewhat).
