Democrats have always ranted about tax cuts not being paid for or tax cuts being the reasons the government has high deficits. They are relatively successful because the Republican PR machine does such a poor job of rebutting it.
First of all, a basic understanding must be communicated to explain the difference between tax revenues and tax rates. Tax cuts are not an actual cut in taxes at all but a reduction in the rate at which income is taxed. Lowering tax rates always increases tax revenues because it encourages investment and spending behavior. This is similar to a store struggling in its' business because sales are sluggish and overhead is always increasing. Does a store like this ever attempt to fix their malaise by simply increasing the prices on their products, when sales are already down? Of course not. Just the opposite. They'll likely run some sales, reducing their margins per item but make up for it in increased sales as a result. When tax rates are reduced, economic activity increases resulting in both businesses paying more in taxes and hiring more people who also pay taxes. This is the reason revenues to the government always increase when tax rates are reduced.
Liberals have never understood the concept. Most are simply too ignorant to grasp it and these are the people, many educated in our intitutions of higher learning, who would never succeed in business themselves. A few do understand it perfectly but keep to their ridiculous rhetoric because, with help from their friends in the main stream press, it continues to play well politically. In their thinking, increasing the rate on the wealthy's income, which has always resulted in a reduction of revenue to the treasury, is somehow an increase in "revenues". Even our poorly educated average high school students should be capable of seeing that for what it is - a farce.
As long as Republicans continue to allow this foolhardy debate to be lead by Democrats and keep talking to everyone as though they were speaking to an audience of lawyers and accountants, socialists politicians will continue to get elected and a strongly needed tax reform bill will never get passed.