As the nonpartisan Congressional Budget Office reaffirmed in a new report this week, the U.S. national debt will skyrocket in the coming decades without significant changes to current law. By 2023, gross debt will soar from $16 trillion to $26 trillion, and will grow "sharply" thereafter.

The CBO attributes this to a combination of the aging of the population and rising health care costs. Medicare is the program where these two factors converge. With more and more seniors demanding increasingly expensive medical care, the program has become unsustainable. Even though these plain facts have been staring him in the face, more than four years into his time in office, President Obama has not only refused to produce a plan that puts the program on a sustainable trajectory, but he's flouted the law in doing so.

In 2003, when Congress passed the Medicare prescription drug plan, lawmakers included a provision that was supposed to force presidents to confront the growing costs of the program. The law stated that each year, the Medicare trustees overseeing the program had to report whether the gap between the cost of the program and its dedicated funding sources exceeded 45 percent. If that level is attained in two straight years, it triggers a "Medicare funding warning," meaning that "the President shall submit to Congress, within the 15-day period beginning on the date of the budget submission to Congress under subsection (a) for the succeeding year, proposed legislation to respond to such warning."

As Medicare's finances deteriorated, this warning was triggered each year beginning in 2007. In 2008, President George W. Bush released Medicare legislation in response, which the Democratic Congress promptly dismissed. However, since becoming president, Obama has ignored the warning for four straight years.

On Monday, Senate Budget Chairman Jeff Sessions, R-Ala., raised the issue in a letter to Jeffrey Zients, acting director of the White House Office of Management and Budget. In a response letter, Zients cited changes to Medicare made as part of Obama's national health care law as satisfying the requirement. But Medicare actuaries have already released three warnings since Obamacare was passed into law, so this does not represent substantive compliance with the law. Zients also argued that the Obama administration "considers the requirement to submit legislation in response to the Medicare funding warning to be advisory and not binding."

Why is the Obama administration trying so hard to avoid offering a plan to put Medicare on a sustainable growth trajectory? The answer goes to how Obama, the Great Divider, governs. He sets aside common-sense attempts to solve problems in favor of political gamesmanship. As long as Obama doesn't present a plan for Medicare, it gives him a free hand to demagogue the issue and politically punish Republicans for wanting to make changes to the program. As outgoing Treasury Secretary Tim Geithner told House Budget Committee Chairman Paul Ryan, R-Wis., last year, "You are right to say we're not coming before you today to say, 'We have a definitive solution to that long-term problem.' What we do know is, we don't like yours."