Senate Majority Leader Mitch McConnell's (R-Ky.) "single biggest regret of my time in Congress," he told Bloomberg News on Tuesday, is "our failure to address the entitlement issue." McConnell said that the mushrooming federal deficit, which the Treasury Department just said grew to $779 billion last fiscal year — 77 percent higher than when McConnell became majority leader in 2015 — is "very disturbing," but he blamed Medicare and Social Security spending, not the $1.5 trillion tax cut he steered through last year.

"I think it's pretty safe to say that entitlement changes, which is the real driver of the debt by any objective standard, may well be difficult if not impossible to achieve when you have unified government," McConnell said. Because cutting Social Security and Medicare are politically toxic, he added, it will be "very difficult to do entitlement reform, and we're talking about Medicare, Social Security, and Medicaid," while Republicans run everything. While top GOP lawmakers have recently proposed cutting Social Security, Medicare, and Medicaid to shrink the deficit, Democrats reiterated Tuesday that they won't be on board if they win one or both houses of Congress.

When advocating for the tax cuts last December, McConnell predicted they would at least pay for themselves due to stronger growth. The White House blamed the ballooning deficits on stagnant tax revenue and higher spending. "Business tax revenue fell sharply in the first nine months of this year because tax rates were cut under last year's law," The Washington Post notes. "McConnell blamed the recent run-up in the deficit on Medicare, Medicaid, and Social Security, but there haven't been policy changes in those programs to explain the major run-up in the debt in the past two years. The bigger changes have instead been bipartisan agreements to remove spending caps on things such as the military, and last year's tax cut." Peter Weber