Roger Simon of Politico has a fine analysis of the Obama speech as he accepted the nomination at the Democratic National convention, saying the candidate highlighted his opponent’s biggest weaknesses: he’s old and wrong.

Obama’s speech soared many times, but it always came back to earth. And it usually came back to earth on John McCain’s head.

Obama mentioned McCain by name no fewer than 21 times, praising his service and patriotism, but attacking him not just on specifics, but on one, general point.

“McCain doesn’t get it,” Obama said. McCain is “grasping at the ideas of the past.”

Need a translation? Here’s one: McCain, who turns 72 on Friday, is old and out of it. His ideas are tired and he is tired, and this is no time in the history of America or the world for a tired president.

You can accuse Barack Obama of a lot of things — and no doubt McCain will do so next week at the Republican National Convention — but you can’t accuse Obama of being a cream puff. He is ready to get it on, high road, low road, or middle road, against the Republicans.

That was certainly how it struck me. Even more, Obama’s speech left me feeling the urgency that we just have to defeat the Republicans this time.

“John McCain stands alone in his stubborn refusal to end a misguided war,” Obama said. “That’s not the judgment we need. That won’t keep America safe. We need a president who can face the threats of the future, not keep grasping at the ideas of the past.”

The past, the past, the past. Old, old, old. Tired, tired, tired. That was Obama’s continuing line of attack as he stood on a vast stage in a vast football stadium looking young, vigorous and enthusiastic.

After seeing and hearing him last night, I can’t wait for the debates. On the one hand, you’ll have the six foot and change young black guy whose energy you can feel through the TV screen. On the other, you’ll have the 5′7″ old white corn dodger with the bizarro smile who has to be photographed from the right in order to keep from scaring young children. Beyond looks, it’s a contest of someone who can articulate his beliefs with alacrity and sincerity versus a guy who, when he isn’t sniping sarcastically, has to check with his staff before stating a position (or how many houses his wife owns).

Bring it on.