Thursday night's is the fourth time he will make a speech at Republican National Convention, but the stakes are much higher this time because McCain is the party's nominee.
When you look around the RNC, to put it mildly or politely, it's somewhat of a homogenous crowd when you look outside of the media at least. But there are several participants who are trying to change that and trying to get the Republican Party to live up to its promise of being a big tent.
Claudio Simpkins is a 23-year-old Harvard Law student from Harlem.
"Dr. King and the entire Civil Rights Movement fought for the freedom to make our on decisions and be our own men. If we decide we disagree on policy issues we should be able to do that," he said.
It is an ethos central to Republicans for Black Empowerment and a spokesperson said despite Obama's historical achievement in winning the Democratic presidential nomination there is a reason to vote Republican.
"But if you look at the values that black churches espouse, they very much match up with the Christian right. It's just we don't vote Republican like the Christian right does. This is an opportunity to show that there's an inclusion for black churches within the Republican Party," said Lenny McAllister, Republicans for Black Empowerment.
Inclusion is a key theme for others, like young people not considered typically important to the GOP winning election. John Fortin is a Chicagoan about to leave his Washington job to organize youth for McCain and away from the Obama movement.
He comes off very well and is a great speaker, but when it comes down to it, it's nothing but a bluff, a façade, how it was at the convention. There are pillars but nothing behind it," said Fortin.
Youth were well-represented at a lunchtime event for the Log Cabin Republicans, a gathering of another atypical instance for the GOP - gays and lesbians. Pennsylvania senator Arlin Specter was there to underscore McCain's endorsement of the group and Specter is promising to make the GOP culture more welcoming.
Specter said he believes the toughest challenge is reasoning with the rank-and-file of the party.
"I think when you sit down and talk to Republicans individually, that they can understand that there ought not to be discrimination of any sort," he said.
The Republican National Committee is not releasing any official numbers about the demographics of its delegates, but some staff called from the Joint Economic Center for Information say there are about 1,900 delegates, and 36 of them are African American. That's about 1.5 percent. In 2004, at the Republican convention, seven percent were African American.
At the Democratic convention in Denver this year, 44 percent of the delegates were minorities, including all minorities, not just African Americans. And also a majority of those delegates were women.
At the RNC, the men outnumber the women 2-1 on the delegate floor. The average age for both parties' convention delegates is 54.