Rep. Brad Sherman (D-Calif.) introduced a bill Wednesday to amend the Presidential Succession Act of 1947 to prevent a member of a different political party than the president from ascending to that office if the commander-in-chief were killed.

The bill’s primary aim is to clarify ambiguities in the original law, which left unclear what would happen if the president, vice president, Speaker and President Pro Tem were killed at the same time. The executive branch would then be headed by the secretary of State, and the House would elect a new Speaker.

Since the Speaker is ahead of the secretary of State in presidential succession, however, there has been some recent discussion about whether the Speaker could then supplant the new president.

“Our friends and enemies around the world, as well as the investment community, should know that in the event of a catastrophe similar policies will continue throughout any four-year presidential term,” Sherman said in a statement, adding that the line of presidential succession “should be as solid as the concrete barriers lining the Capitol grounds.”

The legislation would require the president to file an official document with the Clerk of the House designating the next person in line of succession after the vice president as either the Speaker or the House Minority Leader. The president also would file instructions with the Secretary of the Senate designating the third in line as either the Senate Majority Leader or Minority Leader. (These designations could be revised if either body changed power mid-session.)

A similar bill was introduced earlier this year by Reps. Christopher Cox (R-Calif.) and Martin Frost (D-Texas), who co-chaired a task force last Congress on continuity of government.

Both bills provide that a person who succeeds the president shall serve the remainder of the term and put the secretary of the Homeland Security Department fifth in line of succession. As the law currently stands, the Cabinet secretaries queue for the presidency in the order that their departments were created.

The major difference is that the Cox-Frost bill does not create a party litmus test for ascension to the presidency.

Matthew Farrauto, a spokesman for Sherman, said some of the Congressman’s concerns were not addressed in the legislation already introduced.

“The death of a president at a time when the office of the vice president is vacant could vest the presidency in the opposite political party and radically change federal policy,” Sherman said in a prepared statement.

In related news, Sen. Orrin Hatch (R-Utah) introduced a joint resolution July 10 that seeks to amend the Constitution to make eligible for the office of president a person who has been a United States citizen for 20 years. As the Constitution is currently written, a person who is not born in the United States cannot be elected president.