The key takeaway from President Obama’s big speech last night outlining expanded military action against ISIS is that Congress must debate and vote on it.

Obama is regularly faulted for not having an overarching strategy for the Middle East. But as Peter Beinart has argued, he does have a consistent guiding idea. Obama has “shown a deep reluctance to use military force to solve Middle Eastern problems that don’t directly threaten American lives,” but has “proven ferocious about using military force to kill suspected terrorists.” In the speech last night, Obama reiterated a version of this, claiming we must “use force against anyone who threatens America’s core interests,” but “mobilize partners wherever possible to address broader challenges to international order.”

Similarly, the goal of this mission was defined with reasonable clarity: Destroy ISIS. And Obama seemed clear-eyed about the risks, vowing no ground troops. The more pressing question is this: Has Obama persuasively made the case that ISIS is enough of a threat to merit the response he’s outlined, given all the risks even this action entails? He said this:

ISIL poses a threat to the people of Iraq and Syria and the broader Middle East, including American citizens, personnel and facilities. If left unchecked, these terrorists could pose a growing threat beyond that region, including to the United States. While we have not yet detected specific plotting against our homeland, ISIL leaders have threatened America and our allies. Our intelligence community believes that thousands of foreigners – including Europeans and some Americans – have joined them in Syria and Iraq. Trained and battle-hardened, these fighters could try to return to their home countries and carry out deadly attacks.

Like Dan Drezner, I’m not sure this is enough. And today’s New York Times has a good piece asking whether this is even true in any meaningful sense:

Some officials and terrorism experts believe that the actual danger posed by ISIS has been distorted in hours of television punditry and alarmist statements by politicians, and that there has been little substantive public debate about the unintended consequences of expanding American military action in the Middle East. Daniel Benjamin, who served as the State Department’s top counterterrorism adviser during Mr. Obama’s first term, said the public discussion about the ISIS threat has been a “farce”…

Some American officials warn of the potential danger of a prolonged military campaign in the Middle East, led by the United States, and say there are risks that escalating airstrikes could do the opposite of what they are intended to do and fan the threat of terrorism on American soil.

So, it is not clear how much of a threat ISIS represents to American lives and interests, but it is clear that the escalation could have all sorts of unintended consequences. The statements from some Members of Congress treat the magnitude of the threat — and the idea that it is worth the risks of expanded action — as self evident. We need to hear them justify and explain this. Congress should participate meaningfully in making this decision and it should take partial ownership of the broad assessment underlying it, as well as its consequences, whatever they prove to be.

The suggestion that Members of Congress don’t want to vote on this before the elections is pretty weak. Don’t voters deserve to know where they really stand on hugely consequential questions, beyond anodyne statements? But if not, they can still vote on it after the elections.

* PROGRESSIVES DEMAND VOTE ON WAR: The co-chairs of the Congressional Progressive Caucus have put out a statement on Obama’s speech:

“Congress must weigh in when it comes to confronting ISIL through military action. The voices of the American people must be heard during a full and robust debate in Congress on the use of military force. Speaker Boehner should put legislation authorizing military action on the floor of the House of Representatives before Congress leaves for the upcoming district work period.”

It’s still unclear how many progressives in Congress will actually support the action, but in the interim, they should continue pushing for a vote on it.

* WHY WE NEED A VOTE ON WAR: The Post editorial board explains why, even if one endorses the general goals of the mission, there still should be a vote on it:

Congress has a duty to go beyond writing the check; it should debate the policy and vote to authorize this mission. Though he believes that he already has the authority to conduct this new campaign, Mr. Obama said Wednesday night that he would welcome congressional action, on the sound principle that “we are strongest as a nation when the president and Congress work together.” Congressional and public debate are especially necessary to help strengthen those parts of Mr. Obama’s strategy that remain open to question.

* REPUBLICANS SEE FOREIGN POLICY AS WINNER: National Journal reports that GOP operatives are absolutely convinced that new foreign policy challenges will shower them with political gold this fall:

The GOP argument goes something like this: The summer’s foreign policy headlines, with the rise of ISIS in the Middle East and Russia’s encroaching power in Ukraine, are — coupled with economic concerns, the border crisis, and Obamacare — further proof of Obama’s incompetence as chief executive. Democratic candidates in key races, particularly incumbents who’ve frequently voted with Obama, will support his initiatives overseas. Therefore, voters who want to change the course of the country’s leadership should vote against Democratic candidates this fall.

Watch for Tom Cotton in Arkansas and Joni Ernst in Iowa to stress their military backgrounds even more so than before. Also, if Republicans say something is a political winner for them, it must be true, always and forever.

* VULNERABLE DEMS HIT OBAMA OVER SPEECH: Alexandra Jaffe catches an interesting dynamic: Dem Senate incumbents in tough races, such as Mark Udall in Colorado and Mark Begich in Alaska, quickly criticized Obama’s speech. The key thing here is that they are hitting Obama from the left, with Udall demanding a Congressional vote and Begich expressing grave concerns about arming the rebels.

* ODDS OF GOP SENATE INCREASING? The folks at Larry Sabato’s Crytal Ball have shifted the Arkansas Senate race to “lean Republican” from “toss up,” citing recent polls showing Dem Mark Pryor trailing. Conclusion:

Our new range is a Republican net of five to eight Senate seats…If one assumes Republicans will net Montana, South Dakota, and West Virginia, they need at least two more seats to meet the low end of our range. Arkansas looks like the next domino to fall, and if that comes to pass, the GOP will have netted four seats…Given the wide range of other targets for Republicans in the Senate — Alaska, Colorado, Iowa, Louisiana, and North Carolina, with other conceivable but more remote possibilities in Michigan, Minnesota, and New Hampshire — it seems reasonable to expect that the GOP will net at least one more assuming they don’t lose any of their current seats.

I think it’s premature to shift Arkansas, but I agree that the polling and fundamentals mean the GOP is marginally favored to take the Senate.

* DEM HAS BIG LEAD IN PENNSYLVANIA: A new Quinnipiac poll finds that Democratic businessman Tom Wolf has an enormous lead against Republican Governor Tom Corbett, 59-35. Interestingly, this comes after Corbett had finally embraced a version of Obamacare’s Medicare expansion after many months of negotiations with the administration, in what looked like an effort to turn his fortunes around.

* AND GUN RIGHTS EXPAND ON STATE LEVEL: Missouri lawmakers have voted to expand gun rights in schools, passing a new law that will allow trained school employees to carry guns. This is notable:

The vote makes Missouri the 10th state to pass legislation allowing armed school employees since 20 children and six adults died during a mass shooting at Sandy Hook Elementary School in Newtown, Connecticut, in 2012.

It’s another reminder that, with Republicans successfully blocking any action in Congress, the gun battle continues to rage on the level of the states.

What else?