Democrats face a tough dilemma in dealing with the looming crisis caused by underfunded multiemployer pension plans: Fight for their friends or give them the bitter medicine they may need.

Democrats’ labor allies will take the worst of it if the pension plans, which cover an estimated 10 million workers in heavily unionized industries, start dying. Many are listed as critical and declining by the government. But Republicans call the Democrats’ preferred solution little more than a bailout and are demanding fundamental reform instead, an approach that would likely result in the plans’ beneficiaries getting less than they were promised and would anger unions.