There are two interesting things about this.
First, Madonna is giving a full-on performance of false solidarity. Real solidarity is when we are loyal to those we are connected to in some way, such as our family, or community, or coethnics. But it is more common now to think of solidarity falsely as meaning a compassionate identification with those we hold to be outsiders or marginalised or oppressed.
The latter is false because it is a confusion of categories. Compassion for those who are suffering is undoubtedly a good thing. But it is not the proper basis of solidarity. I should have a sense of solidarity with my own sons even if they are not marginalised or suffering.
Look at Madonna's performance. Flanked by some black male dancers she says to the crowd:
In 1864 Abraham Lincoln was the president of the United States. And what was he fighting for? To abolish slavery. For freedom. And they killed him. As they do. All the prophets. And a hundred years later Martin Luther King Jnr came here to march for the civil rights movement and he won but they killed him. As they do. And now it is so amazing and incredible to think we have an African-American in the White House. Those fine human beings did not die for nothing. They fought for our freedom. Not just African-Americans, but for all people of colour. For people that are different, unconventional, for people who want to believe in what they want to believe. Am I with you? Are you with me? Then that would be a f..... yeah. So, y'all better vote for f....ing Obama, OK? For better or for worse, we have a black Muslim in the White House. Now, that is some sh...t, it's amazing sh..t, it means there is hope in this country. And Obama is fighting for gay rights. So support the man godammit.
So we have this very white looking woman who identifies with those she thinks are most oppressed and most othered: blacks, Muslims, gays. She says that Lincoln and MLK fought for "our" freedom - not just African-Americans but all people of colour. She seems to think of herself as part of an "our" which does not include white people. Her current boyfriend, Brahim Zaibat, fits this identity, as he is of Moroccan (of North African Muslim) descent. She is even keen to think of Barack Obama as a Muslim as that would make her identification with him more complete.
The second interesting thing is that Madonna clearly wants to be seen as a hip kind of non-conformist rebel. Hence the berets, the closed fist salute from the dancer flanking her, the swearing, the invocation of "people that are different, unconventional ... people who want to believe in what they want to believe".
But this is a mask. Madonna's message is the ruling, orthodox, establishment one. She is a voice of the ruling ideology of state (and to some extent of church). If she had wanted to be a rebel she could have shown some loyalty to her own people and her own tradition. But she didn't - she went along with a concept of solidarity that is now mainstream in Western societies. Her radical posturing is a cover up for what she really is: a spokeswoman for a liberal establishment.