Seth Barrett Tillman and I published a new essay on Lawfare. We discuss a theory of "bribery" for the impeachment clause. Here is an excerpt:

Just as the executive branch should not investigate and prosecute horse-trading and log-rolling by members of Congress, Congress should not investigate and impeach horse-trading by the president. Where the president acts for mixed motives while engaging in log-rolling and horse-trading—entertaining related considerations of public policy, his party's success and his chances of personal reelection—there is nothing to investigate.

Judge Frank Easterbrook stated this principle in even stronger terms regarding the conviction and sentencing of Illinois Governor Rod Blagojevich, who offered to appoint Valerie Jarrett, a close associate of President-elect Obama, to a vacant U.S. Senate seat, in exchange for Blagojevich's receiving an appointment to the Obama cabinet. Blagojevich was convicted on multiple counts. On appeal, in U.S. v. Blagojevich (2015), the U.S. Court of Appeals for the Seventh Circuit found that particular counts of his conviction could not stand. Judge Easterbrook explained that "a proposal to trade one public act for another, a form of logrolling, is fundamentally unlike the swap of an official act for a private payment." He added that "[g]overnance would hardly be possible without" political log-rolling, "which allow[s] each public official to achieve more of his principal objective while surrendering something about which he cares less, but the other politician cares more strongly."

Thus, according to Easterbrook, in such circumstances, even mixed motives are irrelevant. Such acts are presumptively lawful, and should not be investigated, let alone be considered for indictment or impeachment. If there is any evidence that there was some sort of secret benefit (such as a suitcase full of cash), then the government can investigate and, if warranted, prosecute that additional act. The secretness of the benefit is evidence of corrupt intent. Where one public official act is traded for another public official act, there has not been any illegal conduct.

We can think of one high-profile and far more brazen effort by a president to improve his party's prospects through the use of official communications. In 1864, during the height of the Civil War, President Lincoln encouraged Gen. William Tecumseh Sherman to allow soldiers in the field to return to Indiana to vote. What was his primary motivation? It was to make sure that the government of Indiana remained in the hands of Republican loyalists who wished to continue the war until victory. This action risked undercutting the military effort by depleting the ranks. Lincoln had dueling motives. Privately, he sought to secure a victory for his party. This personal interest should not impugn his public motive: win the war and secure the nation.