CNN Contributor David Gergen gives McCain a ‘B’ and Obama a ‘B+’

(CNN)–A few hits, some runs and no major errors — that was the way this second debate struck me. The format was far too confining so that neither candidate could answer in depth and viewers were left with a sense of disappointment that they hadn't heard enough about specifics. Too often, we heard the same arguments we heard in the last debate.

Watch: McCain, Obama explain why voters should trust them

John McCain was more effective on domestic issues than he was on the second debate but flatter on national security. Periodically, he made an excellent argument and he was more composed than earlier. Interestingly, he never went as negative as feared (e.g., he never talked — as Sarah Palin has on the stump — about the past associations of his opponent).

Barack Obama showed once again that he is more articulate and a better debater, able to weave together arguments and themes with great skill. Once again he was also steady. But he was hardly on fire and he didn't give us much more insight — or new ideas — about the economic crisis now gripping the country.

So, my scores tonight are lower than last week:
McCain B
Obama B plus

Politically, this debate strikes me as good news for Obama and bad news for McCain. With two straight victories under his belt, Obama has established in the minds of many voters that he is as qualified to be President as McCain –and given the economy, that means he should have strengthened his position.