WASHINGTON — Key Senate Republicans are divided over a GOP colleague’s bill that would allow families of Sept. 11 victims to sue the government of Saudi Arabia.In a political twist, Senate Democrats firmly back the legislation even though it puts them at odds with the White House. Blurring the picture further, House Minority Leader Nancy Pelosi, D-Calif., today expressed skepticism, telling reporters the bill could lead to “collateral damage” and needs to be examined more carefully.President Barack …