Court-packing becomes new litmus test on left

Whether or not to expand the Supreme Court is emerging as a key litmus test in the crowded 2020 Democratic presidential primary field.

Once dismissed as a fringe idea, reforming the nation’s highest court is gaining traction with a growing number of Democratic 2020 candidates as progressive outside groups and high-profile officials, including former Attorney General Eric Holder, have vaulted the idea into the national spotlight.

The courts have emerged as a lightning rod during the Trump administration for the Democratic Party’s resurgent base, which remains deeply bitter over Senate...