I suspect most churchgoers had a hard time imagining someone being in a church with a minister like that unless he shared those views.
I disagree...let's look at Catholics. Many Catholics approve of abortion, yet none of their priests do. Should they not attend church because of that?
Just because you support your minister, doesn't mean you approve of every word he says. Eventually, whether because of the election or not, Obama had to split with Wright. From my article:
Last March, when video clips of Wright damning America blitzed the airwaves, Obama wrote a speech about race that he hoped would save his campaign. But it was, to some, also a speech about faith. Obama tried to explain his relationship with his pastor, to appeal to Americans' sense of the best in themselves. He spoke of racial divides in America as "a part of ourselves we have yet to perfect," and of his pastor as a flawed, human creature. "That speech," says Paul Elie, the Catholic author of "The Life You Save May Be Your Own," "is steeped in Christianity. We have relationships, they're all flawed, we're all broken. You can't renounce your history with a person at a stroke, we have to fare forward with other imperfect people and resist the claims to perfection coming from both sides." After Wright's performance a month later at the National Press Club, Elie says, Obama was right—and Christian—to repudiate him.
Obama wouldn't be the first politician to use their church membership for political gain, but for mainstream America, but that church is not mainstream, regardless of the denomination it belongs to.
Hence my question. What do you consider a "mainstream" church?