Sean Higgins of the Washington Examiner explains why union honchos are watching with concern as Justice Neil Gorsuch joins the U.S. Supreme Court.

Organized labor and its allies in the Democratic Party are bracing for a major hit to union power now that Justice Neil Gorsuch has a seat on the Supreme Court, fearing that he will tip the balance of the court toward overturning key legal precedents that benefit labor.

“This justice is poised to cast the fifth vote to make it next to impossible for public-sector labor unions to organize,” said Tom Perez, chairman of the Democratic National Committee and former secretary of labor, in a speech Tuesday to the United Steelworkers union.

The two main cases on the court’s horizon that unions are worried about are Yohn v. California Teachers Association and Janus v. AFSCME. Both could overturn a 1979 precedent called Abood that said public-sector workers could be forced to join a union or support one financially as a condition of employment.

Such requirements — called “security clauses” in union parlance — are a common feature of public-sector union contracts. They are a key source of the unions’ strength since they boost both membership and dues revenue.