Once billed as a temporary crisis measure to keep Congress running and lawmakers protected as a deadly pandemic ripped across the country, the proxy voting system has become a tool of personal and political convenience for many House members.

Fourteen months after it was approved, with the public health threat in retreat and most members of Congress vaccinated, a growing number of lawmakers are using the practice to attend political events, double down on work back home or simply avoid a long commute to Washington.

Perhaps no one has benefited more from the arrangement than Speaker Nancy Pelosi, who recently informed lawmakers that proxy voting would be in effect for the remainder of the summer. It has allowed Ms. Pelosi, whose majority is so slim that she can afford to lose no more than four Democrats if every member is present and voting, to all but ensure that absences alone do not cost her pivotal support.