A senator can take stands for sheer political purposes. A president doesn't always believe he has that luxury.

Case in point: Barack Obama.

When he was a junior senator from Illinois, Obama once voted against lifting the debt ceiling, a shot at Republican President George W. Bush's "reckless fiscal policies."

As president, of course, Obama came to realize that the debt ceiling is serious stuff. He  labored mightily this spring to persuade Congress to raise the cap, warning of catastrophic consequences should the nation default. Obama’s 2006 vote against lifting the ceiling, his press spokesman said, was "a mistake."

Obama took another stand as senator on a straight-forward principle: The government shouldn't reward tax cheats. He co-sponsored a bill in December 2007 that stated "it is the policy of the U.S. government that no government contracts or grants should be awarded to individuals or companies with seriously delinquent tax debts."

That measure died, but the issue lives on.

Winding through Congress is a bill by Rep. Jack Kingston (R-Ga.) that provides funding for certain government programs. One provision bars contracts to corporations with federal tax liabilities.

The measure has passed the House and is pending in the Senate.

Earlier this month, the Obama administration released a seven-page evaluation of the bill.

"Fighting waste, fraud and abuse" is an important goal, read the statement from the Office of Management and Budget.

But the administration isn't entirely on board with the bit about unpaid taxes.

That provision would "deny agencies the ability to make informed decisions about contracts, grants and other federal assistance," the statement reads. A consequence of the measure could be "unwarranted penalties on businesses and unjustified costs on taxpayers."

An administration official elaborated on this point.

The bill would, in every instance, ban contracts to those who are convicted felons or delinquent in their taxes, according to the official.

"That's a problem because there may be reasons why a firm should be eligible for a contract or grant, despite the tax delinquency or past felony," the official  wrote in an email Wednesday. "Mitigating circumstances might include, for example, that the firm has taken steps to change its business processes to prevent future misconduct, or fired the individuals involved in the misconduct."

The Obama administration wants more discretion. Rather than withhold contracts "automatically," the administration wants to examine "the facts and circumstances" and then make a judgment.

It’s unclear what Sen. Obama, circa 2007, might have thought about that stance.