The nation’s biggest gay rights group is trying to force Sen. Barrack Obama (D-Ill.) to cancel presidential campaign event with a controversial preacher who claims he was homosexual but has been cured. The Human Rights Campaign has expressed its strong reservations to Obama over his campaign-sponsored tour that features gospel singer Donnie McClurkin. The influential organization, representing a powerful Democratic constituency, let Obama’s campaign know that it would issue a public demand if Obama did not immediately cancel the event, said a person who had been briefed on the exchange. Obama will not be present on the so-called Embrace the...