If the offer to Sestak is illegal, then what isn't?

Is it legal for a presidential candidate to offer the vice presidency to a rival in return for his or her support? Is it legal for a Senator or member of Congress to offer his or her campaign workers jobs on his staff in return for their support? That's the surprising legal upshot of Congressman Issa's ethics charges against the Obama administration in connection with the administration's attempts to get Joe Sestak to drop his ultimately successful challenge to Arlen Specter in the Pennsylvania Democratic Senate primary.

The applicable statute is awfully broad:

18 U.S.C. § 600. Promise of employment or other benefit for political activity:

Whoever, directly or indirectly, promises any employment, position, compensation, contract, appointment, or other benefit, provided for or made possible in whole or in part by any Act of Congress, or any special consideration in obtaining any such benefit, to any person as consideration, favor, or reward for any political activity or for the support of or opposition to any candidate or any political party in connection with any general or special election to any political office, or in connection with any primary election or political convention or caucus held to select candidates for any political office, shall be fined under this title or imprisoned not more than one year, or both.

The law was passed in 1948 as part of a revision of Title 18 of the United States Code, "Crimes and Criminal Procedure," and I haven't been able to hunt down any interesting legislative history as to who wrote this law or whether there was any debate. But it's undeniably sweeping in its language: Congressman Issa has picked up on this, as has the blogosphere.

There's an intelligent post about the matter here by Richard Painter, who was "the chief ethics lawyer for the President, White House employees and senior nominees to Senate-confirmed positions in the Executive Branch" from 2005-07 (i.e., under President George W. Bush), the gist of which can be gathered from its title: "Joe Sestak’s 'Bribe' Scandal: Another Ethics Sideshow."

Under this statute, was it legal for President Reagan to offer a "position" (Vice President) to George H.W. Bush in return for Bush's "support of" the Presidential candidate, Reagan, in the presidential elections of 1980 and 1984?

Ditto Clinton and Gore in 1992 and 1996?

Ditto, basically, all vice presidents, and a whole lot of Cabinet members?

And let's not limit this to the executive branch of the government: Under this statute, was it legal for Congressman Issa to offer his campaign workers, "directly or indirectly," future jobs on his congressional staff in return for their political activities on his behalf during his congressional campaigns?

Ditto every Senator and member of Congress?

If so, then maybe they all belong in jail.

Andrew Jackson would have loved this statute: he would have been able to add Issa-esque threats of impeachment and felony to his cries of "Corrupt Bargain!" when J.Q. Adams appointed Henry Clay as Secretary of State.

On the other hand, once safely elected, I imagine that Old "To The Victor Belongs the Spoils" Hickory would have acted quickly to repeal the law: it hardly seems in harmony with Jackson's belief in "promoting that rotation which constitutes a leading principle in the republican creed" a/k/a the "spoils system."