When House Democratic leaders were designing legislation that attached a withdrawal deadline to $100 billion in supplemental funding for the Iraq War, they initially included a provision stating that President Bush couldn’t use military force against Iran without obtaining a Congressional OK. For many Democrats, this was a no-brainer. At an issues retreat in early February, retired Gen. John Hoar had told House Democrats there was a high probability of military confrontation. Some Democratic legislators were looking to cut Bush off at the pass. “Once burned, shame on you; twice burned, shame on me,” says liberal Representative Jim McDermott. But as John Larson, vice chair of the House Democratic caucus and co-sponsor of a similar Iran measure, recalls, “A funny thing happened on the way to the forum.” The Iran provision was pulled out of the Iraq bill.

Appropriations Committee chair David Obey, who had drafted the Iran provision, had an explanation for disappointed fellow Democrats: He had concluded that it was poorly written and Bush could easily circumvent it. But several conservative Blue Dog Democrats had complained about limiting Bush’s options regarding Iran, and Speaker Nancy Pelosi, looking for votes to pass the Iraq War spending bill, decided to appease them. (Her calculation paid off: The bill passed on a 218-to-212 vote.) Days after the Iran measure was yanked, an upset McDermott spoke at a meeting of House Democrats. “We have to make a decision,” he recalls saying, “whether to leave this guy [Bush] with a blank check.” Pelosi promised they’d have the chance to vote on the issue.

But politics and policy are in the details. Pelosi could green-light a stand-alone bill compelling Bush to seek Congressional authority before initiating military action, or she could attach such language to a piece of must-pass legislation, such as the defense authorization bill. House Democrats may not have enough votes to pass separate legislation. Last June Representative Maurice Hinchey proposed an amendment that would have prohibited military action against Iran unless Congress first declared war. It was soundly defeated, with forty-seven Democrats voting nay. (A year earlier Peter DeFazio won only 136 votes for a similar measure.) Although the Democrats have since gained the majority, House aides estimate that there are still dozens of Democrats who would not vote for such a measure. And only five Republicans have supported legislation proposed by Republican Walter Jones that would allow the President to use military force against Iran only after receiving “specific authorization” from Congress (unless Iran attacks the United States or is about to do so). Moreover, Democrat Tom Lantos, chair of the Foreign Affairs Committee, is pushing legislation to intensify sanctions against Iran; and some Democrats would prefer to see get-tough action define their party’s Iran policy, not legislation limiting Bush’s power.

House Democratic aides note the possibility of combining sanctions with restrictions on Bush. But that would not be to the liking of AIPAC, the powerhouse pro-Israel lobby, which has declared the Lantos bill a top priority. In a recent speech AIPAC executive director Howard Kohr said that legislation restricting Bush’s options would be “a sign of weakness.” Asked if he can point to a political fight lost by AIPAC recently, Representative Larson replied, “Not to my recollection.” But if Pelosi tucks an Iran provision into a compulsory bill, it will have a better chance.

In the Senate, freshman Democrat James Webb has introduced legislation to prohibit Bush from striking Iran without Congressional authority unless it’s to counter actual or imminent attack. After taking office Webb reviewed Bush’s signing statement for the bill granting him permission to use force against Iraq and saw that Bush insisted he had “constitutional authority to use force” to “respond to aggression or other threats to U.S. interests.” This claim was “so broad,” Webb thought, that Congress had to prevent Bush from applying it to Iran. Webb had hoped to include his bill in the Senate’s Iraq-funding legislation, but the legislation was passed without it. Majority leader Harry Reid supports the idea underlying Webb’s proposal. But some Democrats fear that such initiatives imply that Bush has the authority to attack Iran unless Congress declares otherwise, and that if a bill like Webb’s were defeated, Bush’s hand would be strengthened. “I understand the concern,” says Webb, “and I’m not taking any options off the table, just trying to rein in a trigger-happy President.”

But before Iran comes Iraq. House and Senate Democrats must still work out a compromise that resolves the differences in each body’s Iraq measure. Then they may find themselves in a constitutional showdown with a veto-wielding President. This won’t leave much time for a debate over Iran. Given rising tensions between the Administration and Tehran, DeFazio says, “we may not even get to send the President a message before something happens.”