President Obama and a key outside ally are stepping up efforts to ensure passage of the massive economic stimulus package, reaching out to Congress with both carrots and sticks. While the president and his top aides are using all the trappings of the office, courting members through phone calls, cocktail parties, West Wing sit-downs and even a politically mixed Super Bowl party, liberal groups are dispensing with the niceties and seeking to drive a wedge between Republicans and one of the right’s most influential leaders.