Tax cuts do not cost anything.<quoted text>
"Over the next 10 years, total tax-cut costs will equal $3.9 trillion"
And they are no longer "tax cuts". They are the Internal Revenue Code.
To allow their expiration is a "tax increase".
Supporting the former tax cuts is not proposing cutting taxes.
Tax cuts are free. Not spending money you never had doesn't cost anything.
Even if it did, your analysis you cited would still be wrong. It assumes static scoring of taxes. It assumes people keeping more of the money they earn has no effect on economic activity. In reality, that money has a multiplier effect as it is active in the economy. This economic activity generates tax revenue. To assume a decrease in tax rates amounts to the corresponding decrease in revenue is provably false.
When Kennedy cut tax rates and Reagan cut tax rates, revenue to the federal treasury increased.