Attorney General Eric Holder was at Northwestern University law school Monday explaining President Barack Obama's claimed authority to kill any American if he unilaterally determines them to be a threat to the nation. The choice of a law school was a curious place for discussion of authoritarian powers. Obama has replaced the constitutional protections afforded to citizens with a "trust me" pledge that Holder repeated Monday at Northwestern.

The good news is that Holder promised not to hunt citizens for sport. Holder proclaimed that:

"The president may use force abroad against a senior operational leader of a foreign terrorist organization with which the United States is at war – even if that individual happens to be a US citizen."

The use of the word "abroad" is interesting since senior administration officials have asserted that the president may kill an American anywhere and anytime, including in the United States. Holder's speech does not materially limit that claimed authority. He merely assures citizens that Obama will only kill those of us he finds abroad and a significant threat. Notably, Holder added, "Our legal authority is not limited to the battlefields in Afghanistan."

The Obama administration continues to stonewall efforts to get it to acknowledge the existence of a memo authorizing the killing of Anwar al-Awlaki. Democrats previously demanded the "torture memos" of the Bush administration that revealed both poor legal analysis by Judge Jay Bybee and Professor John Yoo to justify torture. Now, however, Democrats are largely silent in the face of a president claiming the right to unilaterally kill citizens.

Holder became particularly cryptic in his assurance of caution in the use of this power, insisting that they will kill citizens only with "the consent of the nation involved or after a determination that the nation is unable or unwilling to deal effectively with a threat to the United States." What on earth does that mean?

This is precisely why the framers of the US constitution rejected the "trust me" approach to government, as discussed in this column. Since last year, US drones have killed three Americans overseas.

• This article was originally published on the author's blog and is crossposted here by permission