They call themselves Main Street Republicans, moderates consigned to the back alleys of politics by their own party. But despite a severe bruising in the fall election, this minority within a minority finds itself with new avenues to explore, including working more closely with Democrats. The Republican Main Street Partnership, a leading voice of GOP moderates in Congress, lost seven of its 48 House members to Democratic challengers in the November election. Two other senior members, Rep. Sherwood Boehlert, R-N.Y., and Jim Kolbe, R-Ariz., are retiring. The group also saw Sen. Lincoln Chafee, R-R.I., one of its eight Senate members...