The Presidential Succession Act is flawed. Among other things, putting congressional leaders in the line means that a terrorist could shift control of the presidency from one party to the other. The president pro tem of the Senate follows the House speaker, which means that the line of succession includes a post whose occupants have always been elderly and often been unable to carry out presidential duties.
Matt Glassman at LegBranch.org:
Fortunately, however, improving the Succession Act is straightforward. The first step is to—once and for all—remove legislative branch officials from the line in all cases except disputed elections that stretch past inauguration (when no cabinet exists and prioritizing duly elected officials over administration continuity makes sense). Next, the president should be authorized to set the order of cabinet succession by public executive order from among Senate-confirmed department heads. And finally, to diminish ambiguity around the determination of ‘inability’ in the first place, the decision and operation of the act should mimic the 25th amendment, providing that the next cabinet official in line, backed by a majority of the cabinet, has the authority to declare the vice-president (and president, if necessary) incapacitated. Historically, Congress has only updated succession planning after events expose weaknesses. For example, the 1886 and 1947 revisions followed deaths of sitting presidents. The 25th amendment was based, in part, on informal arrangements President Eisenhower made due to health problems during his presidency. But, planning this important is always better and more effective when it’s done proactively. And while the unlikely possibility of needing to invoke the Succession Act makes it easy to ignore its flaws, current events don’t require a prophet to predict the potentially calamitous result of kicking this particular can down the road. The time to act is now.