A definition for politics that I give my students at San Antonio College is very simplistic but also quite comprehensive. Politics is the pursuit of power in order to exercise power, and different countries use different methods in the pursuit.

In some countries, it is actualized through revolution. In our country, power is achieved through the electoral process. It is not a permanent fixture that belongs to any one political party or person. It is up for grabs every four years, and will accrue to the candidate who recognizes that he/she is in the pursuit and must demonstrate to the voters, through actions, that he or she really deserves the right to exercise power.

This can be an especially difficult task for an incumbent seeking four more years in the White House. After exercising immense power, he must revert back to the pursuit. A sitting president running for re-election is in a very precarious position because he must wear two hats and become two personalities. He is still president but is also, once again, a candidate.

In the past, many presidents have struggled to make that transition. This failure usually becomes apparent in the first debate in which the incumbent engages the challenger on a number of issues. Jimmy Carter failed in his first debate with Ronald Reagan. Reagan failed in his debate with Walter Mondale, both George H.W. and George W. Bush failed in their first debates with Bill Clinton and John Kerry, respectively.

President Barack Obama was caught in that same trap with Mitt Romney in their first encounter. He acted like Romney was supposed to respect him as the president and not just view him as a candidate. That was a major error on his part and he paid dearly for it. He allowed Romney back into the race.

Evidently, President Obama made the proper transition on Tuesday in his second debate, when he acted like a candidate. He was much more energized, alert, knowledgeable and displayed a passion for the people and for the office that reminded us of the old Obama of 2008.

The president definitely brought his “A” game that night. He gave Romney no room to dominate the floor through intimidation. He called the challenger on his many distortions of the president's record and was masterful on the one issue where Romney assumed he had an advantage. When the president stared at the challenger and scolded Romney for politicizing the killing of four Americans, including our ambassador to Libya, the victory was his. But to make sure there was no doubt as to who was the winner, he closed out a very impressive comeback when he reminded the viewers that Romney does not respect 47 percent of the American population.

It now appears that the final debate on foreign affairs should belong to Obama. If, for the next 18 days, the president remains cognizant of the fact that he is once again in the pursuit of power, then his chances for re-election are excellent.