Frustrated by the party’s performance on Capitol Hill and emboldened by the mass protests against President Donald Trump, a coalition of progressive groups say they are open to supporting primary challengers next year against Democratic members of the House and Senate – even if many inside the party believe that intra-party races might ultimately only help the Republican Party gain more power. The organizations, many run by former members of Bernie Sanders’ insurgent presidential campaign, say they haven’t drafted a list of targets just yet.