Audio Transcript:

Marco Werman: I'm Marco Werman. This is The World. President Obama scored some key Republican support for his Syria plan today. House Speaker John Boehner came out in favor of a military strike in Syria. But there's still a lot of work for the administration to do before Congress votes Obama's way. This afternoon, the President sent his top national security advisors to Capitol Hill. Defense Secretary Chuck Hagel said failure to act on Syria's use of chemical weapons would undermine America's credibility and Secretary of State John Kerry told a key Senate committee that US national security was "absolutely at stake."

John Kerry: We need to send to Syria and to the world, to dictators and to terrorists, to allies and to civilians alike, the unmistakable message that when the United States of America and the world say "never again," we don't mean sometimes, we don't mean somewhere. Never means never.

Werman: Todd Zwillich is following all the jockeying in Congress over Syria. He's Washington correspondent with our partners at The Takeaway.

Todd Zwillich: Marco, there are a whole bunch of factions and coalitions in Congress that are going to come to light as part of this debate. Let's start on the Democratic side of the aisle if you want to. There are Democratic pro-Israel hawks. You could have counted Hillary Clinton as one of them. Chuck Schumer, I would imagine. Harry Reid, the majority leader, has said that he's on board with authorization for the President to use force here. And you can count several others with them. There are a large number of anti-war progressives, Democrats who are liberals. Didn't vote for Iraq, won't vote for this. Lots of them, Charles Rangel is someone I talked to this week, from New York City, who won't vote for this, probably counts himself among the anti-war progressives. Many members of the Congressional Black Caucus, although certainly not confined to them. And then among the Democrats you have another strain which is interesting. The liberal interventionists, that's what we sort of call them around the Capitol, the types of liberals who think that the United States should use its military might at times when there is a humanitarian crisis, or to protect the weak. They were in favor of Bill Clinton intervening in Kosovo. They thought that the United States should have intervened in Rwanda when there was a genocide there, when we didn't intervene. They think that those are the times, not like an Iraq War where the intelligence is sketchy or bombing a Sudanese pharmaceutical plant like we did back in the '90s. No, they say that these are the times when we should use our American military might, and I think you're going to see a lot of those liberal interventionists vote with the President on that basis because of the use of those chemical weapons.

On the Republican side, many strains as well. The hawks, you know them, John McCain, Lindsey Graham, pro-interventionists, traditional pro-military Republicans. But then you also have a growing strain, and this is going to be really interesting, particularly in the House of Representatives, where the insurgent conservatives, the Tea Partiers, the recent members, on John Boehner's right, anti-interventionists. Some people like John McCain call them increasingly isolationists. How many of them will cast no votes just because, aside from the fact that they may not want to support President Obama, they just don't think the US should be intervening in places overseas. Count Rand Paul among them, Senator Mike Lee, and many, many, many, a couple of dozen House Republican members who, unlike John Boehner and Eric Cantor, two leaders who said today they will back the war resolution, absolutely won't on that basis.

Werman: You know, John McCain and Lindsey Graham and others have been talking about Iran a lot through this whole Syria discussion. They say hitting Bashar al-Assad, if that should happen, Assad being a key ally of Iran, that would be a strategic victory for the US. What are lawmakers you've been speaking to saying about that, about Iran, right now?

Zwillich: Much the same. You say ally, they say client. They very much view this conflict as a proxy fight with Iran looming in the background, and Russia as well, although Russia's support is of a much different strain. Look, this also goes beyond Assad and just the civil war that he's involved in. Don't forget about Hezbollah, also supported by Iran, harbored by Syria, and taking up residence in southern Lebanon, firing rockets at Israel. They look at Hamas, they look at other would-be Iranian clients around the Middle East and say that what they really want to do in a situation like this is, even if it's not a decisive blow, even if it doesn't topple Assad, and these strikes will not topple Assad, sending the message to Iran and to Iran's other clients that if you go too far, the United States, and by the way, we have clients too, how about Israel, we will act and we won't stand idly by.

Werman: Todd Zwillich there, Washington correspondent for The Takeaway.