A weekend in Nebraska isn't everyone's idea of fun, but hundreds of college students are disappointed they won't be able to campaign for Barack Obama there or in other swing states after a mysterious donor backed out. Students from around the country, including a large contingent from UC Berkeley, had planned to spend the weekend before Election Day fanning out to places such as North Carolina, Georgia and other battleground states. And much of the financial burden was to be borne by an American in Italy known as David Gall. But, as of last weekend, Gall is gone, too badly...