The Senate’s Most Vulnerable Democrats

Two senators from states with little in common and at opposite poles of the country found each other this month: Maggie Hassan of New Hampshire and Mark Kelly of Arizona, who banded together to push a gasoline tax holiday.

Their bill — the Gas Prices Relief Act, which would suspend 18.4 cents of federal tax per gallon — soon found two other eager sponsors: Senators Raphael Warnock of Georgia and Catherine Cortez Masto of Nevada.

A gas tax holiday may face dim prospects, but the fact that four of its...