Regarding the Afghanistan resolution, sponsored by Rep. Dennis Kucinich (D-Ohio), Amash said he supports the intent of the measure, but said that, "because of the way the resolution is written, it is unconstitutional and I cannot vote for it."

Amash said the resolution uses a mechanism in the War Powers Resolution that allows Congress to order the president to withdraw forces from abroad, but he said this "legislative veto" is unconstitutional because the Constitution requires all legislation that has the effect of law to "be presented to the president."

"The War Powers Resolution's legislative veto attempts to perform an end-run around the Constitution's presentment requirement," Amash said. "Every president since 1973 has viewed the legislative veto as unconstitutional, and in a different context, the Supreme Court held the mechanism violates the Constitution."

House Foreign Affairs Committee Chairman Howard Berman (D-Calif.) raised another legal question during floor debate on the resolution. He said section 5(c) of the War Powers Resolution allows resolutions calling for troop withdrawal in cases when they are engaged in military action without the approval of Congress.

Berman said Congress approved military action in Afghanistan, which means it is inappropriate for Kucinich's resolution to be based on section 5(c).

Amash also voted "present" in the vote to end federal funding for NPR based on the belief that Congress's attempt to single out NPR in the bill is unconstitutional.

"The bill's treatment of NPR is arguably unconstitutional and definitely violates the rule of law," he said. "The bill is arguably unconstitutional because it likely is a bill of attainder. Article I, Section 9 of the Constitution prohibits Congress from passing bills of attainder. The idea behind the bill of attainder ban is that Congress shouldn't enact laws meant to punish particular persons or entities, because the proper way to punish a wrongdoer is after the accused has been given a chance to defend himself at trial in a court."

Amash has said he would vote "present" whenever he sees the legislation as unconstitutional, when not enough time has been allowed to consider a bill or when he has a personal conflict of interest related to a bill.