Defense hawks such as Republican Sens. John McCain of Arizona and Lindsey Graham of South Carolina criticized the idea of a stunted, short-term attack on Assad's military centers. They want a sustained U.S. effort to support the rebellion over the long term.
"Anything short of this would be an inadequate response to the crimes against humanity that Assad and his forces are committing," they said in a statement. "And it would send the wrong signal to America's friends and allies, the Syrian opposition, the Assad regime, Iran and the world -- all of whom are watching closely what actions America will take."
Meantime, a growing number of lawmakers questioned whether Assad's heinous use of poison gas posed a real threat to America's national security -- the threshold for Obama's decision to intervene in that war.
Democratic Sen. Joe Manchin of West Virginia raised this very argument, saying the nation was weary of war and did not want to enter another one.
"After over a decade of war in the Middle East, there needs to be compelling evidence that there is an imminent threat to the security of the American people or our allies before any military action is taken. I do not believe that this situation meets that threshold," Manchin said.
Rep. Sam Farr, D-Calif., said he could not support a U.S. attack on Assad without the full support of our major U.S. allies "and a firm case that our national security is at risk." But Great Britain is taking a pass and the French may be our only European ally in this fight -- a stunning rebuke of Obama's leadership abroad.
GOP conservatives were raising troubling questions about the aftermath of even a limited U.S. strike. Wouldn't that give the terrorists a rallying cry and recruiting tools in the Middle East, especially in Syria, and bolster its most radical elements?
Obama's speech "leaves many questions, such as who exactly are the 'good guys' in this conflict? And how is American involvement not the fuel for the fire the Muslim Brotherhood and extremists are trying to ignite throughout the region? Cruise missiles are not a strategy," said GOP Rep. Robert Aderholt of Alabama.
Others wondered if Obama, after long deliberation, felt compelled to go it alone because he had already declared that any chemical warfare would cross his "red line." Was he just trying to save face in this latest confrontation with Assad? That's what some of his critics are thinking.
House and Senate leaders aren't planning to lobby their members prior to a vote, letting each decide the issue for themselves. But there is relatively little evidence that rank-and-file Republicans in either body have any desire to give Obama the authorization he seeks.
"I think it's going to be a very tough sell," GOP Rep. Tom Cole of Oklahoma said of the White House's stepped-up lobbying plans. As of now, Cole said he's "leaning no."
More than 80 lawmakers flew back to Washington over the weekend to attend a classified White House briefing in the Capitol. But Congress isn't set to officially return from its month-long recess until Sept. 9. No one is treating this as an emergency.
Obama maintains this is a question of national security, and that Syria's use of chemical weapons represents an imminent threat to the U.S. and our allies. But his decision to delay action for two weeks or more sent this message to Assad: Don't worry, we're not in any hurry to act.
Meantime, the White House is having trouble writing its war resolution, which grants Obama the authority to use force in Syria "as he determines to be necessary and appropriate." Senate Judiciary Committee Chairman Pat Leahy, Vermont Democrat, told reporters the wording is much too vague and won't pass Congress as written.
These are the people who would send the U.S. into yet another war in the Middle East.