Didn't the top income tax rate decrease by something like 2.5%? Doesn't seem like a lot of room for it to have decreased but still be "significantly higher" than it ended up at.
Let's only consider how that effects the top 1% and a rough estimate. Currently that's around 1.73M filers with an average income of 1.4M a year. Under the new tax rules the average 1% will save $40,000 over 480k (will obviously save more under 480k but not counting that). That totals out to be $692B in tax cuts over 10 years or in other words basically 70% of the tax cut deficit based on standard scoring and 138% based on dynamic scoring (obv not exact). So this could have been a revenue neutral tax cut even after a massive tax cut to everyone, just a slightly less of a tax cut to the top 1%.
In other words 70% of the tax plan deficit over the decade is coming from cuts from the top 1%. I would have preferred a different allocation that would have decreased their tax burdens but not by that much. Obviously this doesn't consider many smaller factors but it's a fairly accurate estimate.
I believe it's far more accurate to say that 70% of the tax cut-related deficit is coming from tax cuts to the 1%. The impact on the overall deficit is far less than 70% from those cuts.
It'd probably a lot lower.
You need to consider other code changes. For instance a filer in CA with W2 taxable income of $1.4M saves only $4,500 due to the loss of state income tax deduction offsetting the vast majority of beneficial rate changes.