The Senate Judiciary Committee plans to hold a markup Thursday on a constitutional amendment that would allow states to provide for the temporary replacement of lawmakers if one-fourth of the Members from either chamber are killed or incapacitated.

The proposal, drafted by Sen. John Cornyn (R-Texas), recently garnered the co-sponsorship of Sen. Saxby Chambliss (R-Ga.) and is expected to sail through the subcommittee on the Constitution with little, if any, opposition. If so, that course would contrast sharply with action taken last week by the Judiciary Committee in the House, which reported out adversely an amendment resolution by Rep. Brian Baird (D-Wash.) after a contentious debate and partisan vote.

“Our chief counsel did a lot of shoe leather on this one,” Cornyn spokesman Don Stewart said. He added that if the measure passes easily in subcommittee, it “bodes well” for quick and easy passage by the full panel. “We need to move this thing,” Stewart added.

Cornyn, who chairs the subcommittee, has pressed his colleagues in recent weeks to pay attention to the continuity dilemma, which although more acute in the House, nonetheless could prevent both chambers from functioning after an attack. (Although the 17th Amendment allows for Senate vacancies to be filled by appointment, unlike the House, it does not address the issue of incapacitation, which many experts believe is a much more likely doomsday scenario.)

Cornyn has acknowledged the political reality between the two chambers on this issue and has recently made several statements deferring to the House’s prerogative.

“Though some disagreement remains on what form the solution should take, I will defer to the House to design continuity provisions for their chamber,” he said in a statement following the House markup. “I recognize that some House Members favor emergency interim appointments to ensure immediate continuity of House operations, while others prefer to rely solely on expedited special elections. Under my approach, each state would make its own choice.”

With the introduction of his amendment language and accompanying implementing legislation, Cornyn has attempted to solve the most vexing political and logistical issues of Congressional continuity — namely, how to ensure the legislative branch is able to reconstitute itself quickly in the event of catastrophe, and how to overcome considerable opposition in the House to even temporary appointments.

Cornyn, who has held multiple hearings on the subject, seeks to solve both problems by limiting the duration of temporary appointments to 120 days while leaving the decision about whether to have appointments at all to each state.

Under his plan, the amendment provides Congress the constitutional authority to craft a statute that would allow — but not require — temporary appointments to the House in the event 109 Members are killed or incapacitated and to the Senate if 25 Members are incapacitated.