Time To Drop The Supply Side Lie?

Mark Thoma thinks Republicans use the growth argument as a ruse to attack entitlement programs, since there is no evidence to support their claims of economic growth from tax cuts:

Despite their failed promises, the Republican Party is asking that we extend the tax cuts for the wealthy, and some are even calling for further reductions in tax rates. However, if the Republican Party is truly the party of business, then surely it will understand that no responsible financial institution would continue to invest in a business that failed meet, or even come close to the growth and revenue projections that justified the investment in the first place. The payoffs from tax cuts that were promised during the Bush years have not been realized, and the failed promises about growth and revenue have damaged the health, education, and retirement programs the working class depends upon in our increasingly globalized economy.
A true party of business would end our investment in the false promise of supply-side economics. However, a party with a goal of reducing the scale of programs such as Social Security and Medicare along with delivering tax cuts to wealthy political backers would use arguments about the economic effects of tax cuts to disguise its true intentions. Which description fits best? Many Republicans still claim that tax cuts for the wealthy enhance economic growth despite the evidence to the contrary, but it’s rare to hear a Republican admit that these supply-side policies have failed.

I think the Republicans see pushing for tax cuts continuously as win-win.  If they get tax cuts through, it weakens the government and puts money in their and their supporters' pockets and erodes the government cash flow.  If they can't get tax cuts through, they scream harder that business would be booming if the tax cuts had gone through, even though there is no evidence of that.  Right now, though, Obama is making them flesh out how they plan to balance the budget, and I don't think people will like the details.  So far, though, still no details.