Isn't it pretty to think so?

 David Brooks says that Americans have moved to the left on issues involving the welfare state, and that it's not just a short-term reaction to Trump and the recession caused by the coronavirus.  He says "the 2020 shift to the left follows years of steady leftward drift."  The General Social survey has a number of relevant questions going back to the 1970s:

Placing yourself on a seven point scale from "the government in Washington ought to reduce the income differences between the rich and the poor,perhaps by raising the taxes of wealthy families or by giving income assistance to the poor" to "the government should not concern itself with reducing this income difference between the rich and the poor."

and five point scales for " the government in Washington is trying to do too many things that should be left to individuals and private busienss" to "the government should be doing even more to solve the country's problems", the government doing everything possible to improve the standard of living of poor Americans, the government helping people to pay for doctors and hospital bills, and the government doing everything possible to improve the living standards of blacks.  

The means for the questions (higher values mean more conservative):

It doesn't look like a trend on anything, although the movement on helping blacks from 2014-18 is striking.  If you regress them on party of the president and a time trend, the party effect is statistically significant for all (opinions are more conservative under a Democrat) and the time trend isn't statistically significant for any.  So basically, they've been stable, although opinions about aid to blacks may be starting to change.  

You could argue that the actual role of the government has increased (which it generally has, if you just go by dollars spent), so if you interpret the questions as relative to how things are, then opinion has moved to the left.  That is, people's view of the status quo is stable, but the status quo has moved left.  But Brooks seems to be saying something stronger--that there's increasing public pressure to move farther and faster to the left.

Oddly, I agree with Brooks's concluding remarks:  "It was a vigorous debate that lasted many decades, but the liberal welfare state won — a robust capitalist economy combined with generous social support."  But that victory happened a long time ago--the 1950s or 1960s.  Since then, there hasn't been much change in popular views of the welfare state and redistribution.