This isn't necessarily something we didn't already know, but the evidence that the GOP's tax cuts for the rich haven't made a meaningful difference for average Americans continues to pile up.
A new survey of corporations conducted one year after Republicans used the reconciliation process to pass their tax cuts shows that the vast majority of businesses have not changed their plans.
From NBC News:
The National Association of Business Economics' quarterly business conditions poll, published on Monday, found that while some companies reported accelerating investments because of lower corporate taxes, 84 percent of respondents said they had not changed plans. That compares to 81 percent in the previous survey published in October.
"A large majority of respondents, 84 percent, indicate that one year after its passage, the corporate tax reform has not caused their firms to change hiring or investment plans," said NABE President Kevin Swift. [...]
The NABE survey also suggested a further slowdown in business spending after moderating sharply in the third quarter of 2018. The survey's measure of capital spending fell in January to its lowest level since July 2017. Expectations for capital spending for the next three months also weakened.
I don't know if the Democratic presidential nominee will be up to running on increasing taxes on corporations in 2020, but I believe it can be done by making the case that corporations have not actually benefited from these tax cuts.
It's well documented that the vast majority of the GOP's tax cuts have been passed on to executives and wealthy shareholders, not the average employees who work for corporations and make money for shareholders.
Average workers have seen no significant benefit from the tax cuts and by the time the election arrives we'll be in a new era of trillion dollar deficits that average workers will also be asked to pay for.
If Democrats are looking for a "populist" message in 2020, I don't think it's gets any easier than attacking the GOP's tax cuts for the rich.