The two most commonly used clemency powers are those of pardon and commutation.

The Constitution gives the President broad clemency power, designed to operate after conviction and all appeals are exhausted.

Mr. Kendall said, "Exercise by the president of his constitutional clemency power is almost always controversial."

Under the Constitution, the President's clemency power extends only to federal criminal offenses.

PardonPower.com, blog providing facts, figures and historical data regarding the president's clemency powers.

Much of this commentary obscured the fact that the clemency power provided the President with several options short of a full, unconditional pardon.

Gov. Rick Perry, who holds clemency power, did not immediately rule on the 5-to-1 request for a delay.

Those with clemency powers have to steer between playing God and incurring public wrath.

"I think it's a perversion of the governor's clemency power to say this," he said.

The framers had higher hopes for the clemency power, an all-but-unlimited presidential prerogative.