Circular firing squad.

(The Hill) — A key Senate Democrat on Tuesday tamped down the suggestion by some in his own party that President Obama could be impeached for launching military strikes on Libya.

Sen. Carl Levin (D-Mich.), a supporter of the U.S. mission in Libya and the chairman of the Senate Armed Services Committee, said that if Obama’s actions on Libya are impeachable, then so are the acts of every other president since World War II who launched military operations without a formal declaration of war.

Rep. Dennis Kucinich (Ohio), an anti-war Democrat, has raised the specter of impeachment, though he did not go as far to say that Congress should begin impeachment proceedings against Obama.

“I raised the question in a private phone conversation with other Democrats as to whether or not if a president takes us into a war without consulting — without following the constitution, would that be an impeachable offense. I did raise that question,” Kucinich said on Fox Business network on Monday. “The process of impeachment is a separate thing. I raised the question to challenge what I see is an overreach of executive authority.”

Former presidential candidate Ralph Nader has called for Obama’s impeachment outright over the wars in Iraq and Afghanistan.

Obama penned a letter to Congress on Monday, explaining he had the authority to launch the strikes under his constitutional role as commander in chief. That came after members of Congress in both parties, including Speaker John Boehner (R-Ohio), complained that the president had not adequately explained the U.S. mission to Congress and the public.