On Syria strike, Obama administration ramps up pressure on Congress, shows flexibility As the Obama administration launched what it described as a "flood the zone" campaign to persuade Congress to authorize military action against Syria, officials said Monday that they are willing to rewrite the proposed resolution to clarify that any operation would be limited in scope and duration and would not include the use of ground troops. Their signal of flexibility came amid indications that Obama is picking up tentative, conditional support in what promises to be a difficult battle for approval of military strikes. After meeting with the president Monday at the White House, Sen. John McCain (R-Ariz.) - who has been among the leading Syria hawks - warned that if Congress rejects the resolution, "the consequences would be catastrophic. The credibility of this country with friends and adversaries alike would be shredded, and there would be not only implications for this president but for future presidencies as well. As McCain's comments suggest, lawmakers are approaching their decision with an awareness that its ramifications go well beyond the thorny question at hand, which is how to punish the government of Syrian President Bashar al-Assad for his alleged use of chemical weapons against his own people. A vote is expected shortly after Congress returns to Washington next week. Obama's surprising decision to seek congressional approval, announced Saturday, marks a turning point from recent history, in which presidents have given lawmakers less and less of a role in deciding when and how to take the country to war. Obama was elected in part as a rejection of the George W. Bush administration's push to invade Iraq a decade ago. Yet the negotiations and the outcome on Syria could set a precedent that limits the latitude of future presidents - or makes them wary of consulting Congress at all. Obama has not said what he will do if Congress rejects the strike resolution. The White House maintains that it does not have to seek congressional authorization for the brief military campaign it envisions. Preparations for that operation continued Monday. The aircraft carrier USS Nimitz and other ships in its strike group moved into the Red Sea to help support a strike, if needed, defense officials said. Adding to the challenge of winning congressional approval is the fact that Obama is undertaking it at a time of hyper-partisanship that has produced gridlock on a host of domestic issues. White House officials say they hope that this vote can be elevated from the political morass and made on the merits - a view that has been echoed by influential Republicans, including House Intelligence Committee Chairman Mike Rogers (Mich.). The administration's openness to negotiating new language for its proposed resolution is an attempt to address concerns, voiced on the left and the right, that the draft is too vague. Doing so would also put into writing some of the reassurances that Obama has offered in his statements. "To secure a yes from Congress, the White House will need to make a compelling intelligence presentation, have persuasive answers to questions about what it will do if the Assad government persists in using chemical weapons despite a U.S. military strike, and write authorizing language that is neither too expansive for skeptics nor too limited for hawks," said James Lindsay, director of studies at the Council on Foreign Relations.