In a rare show of agreement, both liberal constitutional law scholar Sandy Levinson and conservative Michael Rappaport argue that the the 1947 presidential Succession in Office Act should be amended to allow the Secretary of State to be third in line for the presidency after the president and vice president (hat tip Instapundit). Under the current system, the line of succession first goes through the Speaker of the House of Representatives and the President pro tempore of the Senate.
As Sandy and Michael both point out, the status quo creates the potential for serious problems. A president who dies, becomes incapacitated, is impeached, or forced to resign might be succeeded by a politician from another party. For example, if Dick Cheney is unable to serve, George W. Bush would be succeeded by incoming Democratic Speaker Nancy Pelosi. From 1995 to 1998, Democrat Bill Clinton could have been succeeded by his political archenemy, Republican House Speaker Newt Gingrich. Divided government is now the normal state of affairs in American politics, so such scenarios are likely to be common.
There is also another weakness in the current system, one that Michael and Sandy don't consider in their posts. Fourth in line under the 1947 act is the president pro tempore of the Senate. By tradition, the president pro temp is the longest-serving Senator of the majority party. The current PPT is Republican porker Ted Stevens of Alaska - soon to be replaced by the Democrats' own "King of Pork," Bob Byrd of West Virginia. In addition to their other shortcomings, both Stevens and Byrd are in their 80s (83 and 89 respectively). This is not accidental. By its very nature, the presidency pro temp is likely to be held by elderly and often infirm politicians. Senators who last for decades are also likely (by virtue of their seniority) to be heavily implicated in porkbarreling and other dubious practices of the world's greatest deliberative body. For these reasons, among others, the PPT should not be included in the line of presidential succession.