I know that I don't look like the Americans who've previously spoken in this great city. The journey that led me here is improbable. My mother was born in the heartland of America, but my father grew up herding goats in Kenya. His father - my grandfather - was a cook, a domestic servant to the British.

Isn't it great to hear a real President speak? Somehow I don't think there have been a lot of conversations about the greatness of America around the Obama dinner table.

Put the fireworks in storage. Cancel the parade. Tuck the soaring speeches in a drawer for another time.

This year, America doesn't deserve to celebrate its birthday. This Fourth of July should be a day of quiet and atonement.

For we have sinned.

We have failed to pay attention. We've settled for lame excuses. We've spit on the memory of those who did that brave, brave thing in Philadelphia 232 years ago.

The America those men founded should never torture a prisoner.

The America they founded should never imprison people for years without charge or hearing.

The America they founded should never ship prisoners to foreign lands, knowing their new jailers might torture them.

Such abuses once were committed by the arrogant crowns of Europe, spawning rebellion.

Today, our nation does such things in the name of our safety. Petrified, unwilling to take the risks that love of liberty demands, we close our eyes.

It already seemed, when I made my visit, that McCain’s opponent might well be Senator Obama, and I was curious to know how Limbaugh planned to take on America’s first African-American major-party nominee. “I’ll approach Obama with fearless honesty,” said Limbaugh, who speaks of himself in heroic terms on air and off. “He’s a liberal. I oppose liberals. That’s all that’s involved here.”

I asked if he had any specific tactics in mind.

“I haven’t yet figured that out exactly,” he said. “You know, I’ve had a problem with substance abuse. I don’t deal with the future anymore. I take things one day at a time.”

In this case, it took two. I was back in New York, listening to the radio, when I heard Limbaugh say: “Ladies and gentlemen, I had a conversation with a friend Wednesday afternoon after the program, and he said, ‘Nobody’s criticizing Obama. How are you going to do this? How are you going to handle criticizing the first black American to run for president?’ I said: ‘I’m going to do it the way I always do it. First, at the top of the list, I’m going to do it fearlessly. I’m not going to bow to political correctness. I’m going to do it with humor. I’m going to focus on the issues. I’m going to react to what he says. Simple. I’m going to do it just like it were any other case — he’s a man, right? He’s a liberal. How do I criticize liberals? I criticize them.’ But I have devised, ladies and gentlemen, an even more creative way of criticizing Obama. I have, just this morning, named a new position here on the staff that is the Official Obama Criticizer. The E.I.B. Network now has an Official Obama Criticizer. He is Bo Snerdly.”

Snerdly introduced himself as an “African-American-in-good-standing-and-certified-black-enough-to-criticize-Obama guy,” and declared that he was speaking, “on behalf of our E.I.B. brothers and sisters in the hood.” The bit was typical Limbaugh — confrontational, deliberately insensitive and funny. It was also a declaration of independence. Whatever special courtesies John McCain might plan to extend to Barack Obama, Limbaugh is going to conduct his air war, as he always has, by his own rules of engagement.

On May 16, Limbaugh delivered a monologue on what you can’t say about Obama: “With Obama we started out, we couldn’t talk about his big ears ’cause that made him nervous. We’ve gone from that to this: Not only can we not mention his ears, we can’t talk about his mother. We can’t talk about his father. We can’t talk about his grandmother unless he does, brings her up as a ‘typical white person.’ We can’t talk about his wife, can’t talk about his preacher, can’t talk about his terrorist friends, can’t talk about his voting record, can’t talk about his religion. We can’t talk about appeasement. We can’t talk about color; we can’t talk about lack of color. We can’t talk about race. We can’t talk about bombers and mobsters who are his friends. We can’t talk about schooling. We can’t talk about his name, ‘Hussein.’ We can’t talk about his lack of experience. Can’t talk about his income. Can’t talk about his flag pin. This started out we can’t call him a liberal. It started out we just couldn’t talk about his ears. Now we can’t say anything about him.”

Limbaugh has been a factor in every national election of the past 20 years, but not since the mid-1990s has he been so prominent. Democrats have blamed him for everything from invading their primaries to starting scurrilous rumors aboutMichelle Obama. Limbaugh denies the latter accusation, but he happily embraces the
former.

His vehicle was so-called Operation Chaos, a radio campaign designed to encourage Republicans to vote for Hillary Clinton and prolong internecine fighting among liberals.

Nobody quite knows how effective Operation Chaos was. Karl Rove said he thinks it helped tilt Texas for Clinton. She herself gave this some credence on the day after the vote by jauntily saying, “Be careful what you wish for, Rush.” Howard Dean implored primary voters in Indiana and North Carolina to ignore Limbaugh. The Obama supporter Arianna Huffington called Limbaugh and other conservative hosts “toxic curiosities.”

After Clinton won in Indiana, where 10 percent of Democratic primary voters admitted to exit pollsters that they were really Republicans, Senator John Kerry accused Limbaugh of “tampering with the primary” and causing Obama’s defeat.

Limbaugh was delighted. He deemed Operation Chaos to have “exceeded all expectations” (his customary self-evaluation) and explained once again that he wasn’t supporting Clinton but merely trying to bloody Obama because John McCain was too chicken to do it and because he believed that Obama would then be easier to beat in November.

We are not shocked when a candidate moves to the center for the general election. But Mr. Obama’s shifts are striking because he was the candidate who proposed to change the face of politics, the man of passionate convictions who did not play old political games.

There are still vital differences between Mr. Obama and Senator John McCain on issues like the war in Iraq, taxes, health care and Supreme Court nominations. We don’t want any “redefining” on these big questions. This country needs change it can believe in.