Washington ? A funny thing is happening on the way to the war. Republicans are fighting among themselves about whether to support President Bush’s “regime change” in Iraq while Democrats are falling all over themselves to back Bush. GOP congressional leaders, worried about losing control of the House and anxious to regain the Senate, are contemplating calling for a vote this fall to put Congress on record behind Bush should he choose to intervene in Iraq militarily. Whether they’re for the war or against it, Republican lawmakers generally agree that anything that returns to the subject of war and away from domestic woes benefits the president’s party.

This is not a new fight for Republicans. Tension between the internationalist and the isolationist wings of the party defined the GOP for much of the last century. Sen. Henry Cabot Lodge’s opposition to President Woodrow Wilson and the Treaty of Versailles set the stage. Then the election of Dwight Eisenhower in 1952 seemed to settle the matter, heralding a line of Republican presidents, from Richard Nixon to George W. Bush, who embraced an activist foreign policy. When commentator Patrick Buchanan tried to revive a strain of isolationism as a presidential candidate, he found himself and his ideas quickly marginalized.

What’s different about the GOP’s internal battle this time around is that many of the participants resisting going to war against Iraq are card-carrying members of the party’s internationalist establishment. Gen. Brent Scowcroft was national security adviser at the time that Bush One organized the coalition to wage the Gulf War. He remains close to former President Bush and consults regularly with the current foreign policy team. Yet Scowcroft is leading the intellectual argument against an imminent invasion, arguing that it will turn the Middle East into a cauldron, derail Bush’s war against terrorism, and cost the United States valued friendships with the Europeans and the Arab states. The flip side, which he dismisses, is that pre-emption is the best way to prevent an attack.

Another respected voice within the GOP who has raised objections to engaging Iraq militarily is Nebraska Sen. Chuck Hagel, a decorated Vietnam veteran who takes an active role in international matters on Capitol Hill. Though a relative newcomer to the foreign policy establishment in Washington, Hagel would be closer to the GOP’s internationalist wing than to its isolationists.

House Majority Leader Dick Armey, who is retiring at the end of this Congress, has also spoken out against the Bush administration taking precipitous action against Iraq. Armey comes from the school of GOP politicians that think if you’ve seen Europe once, you’ve seen it all. Armey is more typical of the head-in-the-sand sentiment that reflexively opposes any overseas involvement.

To his credit as a leader, Bush has shifted the debate from whether we should confront Saddam to when and under what conditions the United States should act. Democrats are not going to get in the middle of that argument. Other than to call on the president to make his case more fully and forcefully than he has so far, Democrats are standing off to the side and letting the Republicans have at each other. The debate has gained momentum in the last weeks because the expectation is that Bush, with time to ponder at his ranch in the waning days of summer, will come to a decision about how to proceed.

The cautionary words of his father’s best friend must weigh heavily. Bush will probably choose to dismiss them as the self-justifications of a man who refuses to accept the gravity of the first Bush administration’s failure to remove Saddam when it had the chance.

Prediction: GOP isolationists will gain strength until America successfully imposes an Iraqi regime change or until another terrorist attack strikes on U.S. soil.

Political Correspondent Eleanor Clift contributed to this column.