Forty-one senators have pledged to filibuster any bipartisan spending bill that includes an amendment to strip federal funding from Planned Parenthood, threatening an impasse with House conservatives.
 
The group, led by Sen. Barbara Boxer (D-Calif.), includes thirty-nine Democratic senators and two Independents, Sens. Joe Lieberman (Conn.) and Bernie Sanders (Vt.).
 
It's just large enough to sustain a filibuster to block any spending bill that cuts Planned Parenthood funding from passing the upper chamber.