PROVIDENCE, R.I. -- Sen. Lincoln Chafee said his knees buckled when he walked into his polling place Tuesday morning and saw that voters were given a prominently displayed option of casting votes along a straight-party line. "It was so easy to just go against the Republicans and fill in that Democrat. It was so easy," Chafee said Thursday in a post-mortem dissection of his loss to Democrat Sheldon Whitehouse. Voters in Rhode Island did exactly that on Tuesday, filling in Democrats in large numbers and sweeping the Republican Chafee from office as part of a fierce backlash that uprooted GOP...