WASHINGTON — Senator McCain is laying out a vision for a four-year term as president that includes a homecoming for American troops from Iraq, congressional passage of a flat tax alternative, and substantial progress on a range of issues from health care to climate change.

Turning a traditional forward-looking stump speech on its head, the presumptive Republican nominee delivered an address in Columbus, Ohio, that painted a picture of what the world would like in 2013 under a President McCain.

“By 2013, America has welcomed home most of the servicemen and -women who have sacrificed terribly so that America might be secure in her freedom. The Iraq war has been won,” Mr. McCain said. “Iraq,” he continued, “is a functioning democracy, although still suffering from the lingering effects of tyranny and centuries of sectarian tension. Violence still occurs, but it is spasmodic and much reduced.”

Osama bin Laden and his top lieutenants will have been killed or captured, the Arizona senator said, and the administration’s newly formed League of Democracies will have hastened the end of the genocide in Darfur.

On the domestic front, Mr. McCain said Congress will finally get the message that he is committed to ending pork-barrel spending — albeit after “several” vetoed bills — and that Americans will have accepted the need to “deal humanely” with illegal immigrants.

America will be “well on the way” to energy independence, and health care costs will be lower, he said, though he does not predict universal coverage, as his Democratic opponents have promised.

“I cannot guarantee I will have achieved these things,” Mr. McCain cautioned. “I am presumptuous enough to think I would be a good president, but not so much so that I believe I can govern by command.”

Still, the four-year forecast was by any measure sunny, and Democrats wasted no time in panning it as a fantasy, particularly Mr. McCain’s vision for Iraq.

“John McCain said that four more years of the same strategy will produce victory in Iraq, though he provided no new approach or new proposals,” Senator Clinton said in a statement, noting that Mr. McCain had predicted victory in Iraq before.

The Democratic National Committee labeled the speech a “fictional account,” and its chairman, Howard Dean, said, “The reality behind Senator McCain’s new rhetoric is that his plans either ignore the problems he identifies or actually makes them worse.”

The president emeritus of the Council on Foreign Relations, Leslie Gelb, called Mr. McCain “one of the most important” voices on foreign policy in America, but he lambasted his address. “It really surprises me to see him giving speeches like the one today that is almost in la-la land,” he told reporters on a conference call, saying Mr. McCain had offered no prescription for how he would achieve victory in Iraq.

In his speech, Mr. McCain also pledged a different style and tone from the Bush administration. In addition to asking Democrats to serve under him, he said he would hold weekly press conferences and take questions before Congress, just as the prime minister of Britain appears regularly before the House of Commons.

He promised a depoliticization of governance, saying he would not judge himself by elections won. “There is a time to campaign and a time to govern,” he said. “If I’m elected president, the era of the permanent campaign will end. The era of problem-solving will begin.”

Acknowledging Mr. McCain’s stated rejection of partisanship, the Obama campaign offered a response that was notably less harsh than either the DNC or Mrs. Clinton, although it was critical. “While Senator Obama agrees with many of the sentiments Senator McCain expressed today, he believes you cannot embrace the destructive policies and divisive political tactics of George Bush and still offer yourself as a candidate of healing and change,” the campaign said in a statement. “That’s simply not straight talk.”