CAIRO — In the end, President Obama made a hugely important but unintended contribution to the democracy revolution in Egypt. Because the Obama team never found the voice to fully endorse the Tahrir Square revolution until it was over, the people in that square now know one very powerful thing: They did this all by themselves. That is so important. One of the most powerful chants I heard in the square on Friday night was: ‘The people made the regime step down.