President Obama is expected to attend at least eight fundraising events around the country over the next five weeks for House and Senate Democrats, sources say. The aggressive cross-country trip comes after a government shutdown battered Republican approval ratings and raised Democratic hopes of keeping control of the Senate and winning back the House for Obama’s final two years in office. Obama enjoyed having his party wield power during his first two years in office, and seeing Rep. Nancy Pelosi (D-Calif.) return to the House speakership would dramatically increase his power while limiting his days as a lame-duck president. The...