Back to town comes Barack Obama, to plummeting polls and sour columns rolling his presidency into the hearse. The memory doesn’t offer much comfort, but the previous two Democratic presidents endured similar rentrées to the nation’s capital.

When Bill Clinton returned from his outing to Martha’s Vineyard in the late summer of 1993, the collapse of his administration was already three months old. He was well into his rebirth cycle as a committed Republican. As an opposing, progressive challenge to business as usual, even by the wan standard of its own timid promises, his presidency had decisively failed by the closing week of May, on the last Saturday of which he signaled surrender by recruiting the old Nixon/Reagan/Bush hand David Gergen as his new public relations chief.

Jimmy Carter achieved his zenith as an agent of positive change on his second day in office: “I, Jimmy Carter, President of the United States, do hereby grant a full, complete and unconditional pardon to: (1) all persons who may have committed any offense between August 4, 1964 and March 28, 1973 in violation of the Military Selective Service Act…and (2) all persons heretofore convicted, irrespective of the date of conviction, of any offense committed between August 4, 1964 and March 28, 1973 in violation of the Military Selective Service Act…restoring to them full political, civil and other rights.”

On August 6, 1979, Carter formally surrendered power by installing Paul Volcker as chairman of the Federal Reserve, tasked with waging war on inflation, with large sacrifices imposed on those who had voted for Carter.

In terms of popularity and political strength, Clinton peaked at the Democratic National Convention in New York. Decline was not long delayed. On election day in November 1992, the long sunset had already commenced. By the time of the inauguration, the Clinton administration was already low in the water. The president-elect and his advisers had destroyed their room for maneuver in the formulation of economic policy. They fanned budget-cutting hysteria by accepting the silly Republican claim that–surprise!–the prospective deficit was going to be more severe than expected.

By the time Clinton took the presidential oath, his presidency was, as anything other than a vehicle for economic orthodoxy and Wall Street wisdom, in the ditch. A few days later, he pushed the wreck into the crusher with his catastrophic handling of the issue of gays in the military. Before the week was out, the Pentagon had its majority in Congress and the Christian right was trumpeting renewal and victory. The health insurance debacle toppled all surviving hopes for constructive change.

It’s hard to know when Obama peaked. Was it at the convention in Denver? Or the election-night rally in Chicago? Or his formal inauguration in January? By the time of his election he had already signed on to Paulson’s bailout of the banks. By the hour Chief Justice Roberts swore him in, he’d chosen as his top economic advisers the bankers’ men, Lawrence Summers and Tim Geithner, with Volcker on the sideline. By the end of his first month we knew Wall Street and Goldman Sachs were firmly in control.

Here we are in September, and what have Obama’s liberal supporters got to cling to by way of evidence that positive change is on the way? Economically, we seem to be heading–well ahead of schedule–into 1937, the year the New Deal crashed onto the rocks. The energy bill, driven by junk science and junk nostrums, has been a detour into disaster. Health reform is levitating toward the graveyard, borne along by Blue Dog Democrats, nerveless salesmanship by the White House and as ripe an eruption of insanity by the know-nothing legions as I’ve ever witnessed. In a way it’s inspiring to see ideological principle trump raw self-interest. Night after night one can see men tottering out from million-dollar life-saving procedures in the VA hospital to hurl invective against “socialized medicine.” Who’d have thought that the “healthcare debate” would be the beard for Klan rallies?

Many Obama dreamers hoped that their man would introduce some minimal shift for the better in America’s relationship with the rest of the world. Now all they have to look forward to is Gen. Stanley McChrystal marching up to Capitol Hill and into the Oval Office to demand more troops for Afghanistan. In relations with Russia Obama and Vice President Biden have remained substantively committed to NATO expansionism. In Latin America, the handling of the coup in Honduras and warm relations with Colombia’s Uribe suggest a sinister larger strategy of counterattack on the leftist trends of the past few years.

It’s a dark vista overall. Some big opportunities–like a frontal assault on the power of the banks and of Wall Street–will never return. What can Obama do to regain the initiative?

There are two men capable of uniting large numbers of Americans in detestation: Dick Cheney and George Bush, in that order. Typically, Obama has hopped from foot to foot on his administration’s posture toward our Home Team Torturers. Now Attorney General Eric Holder has gingerly inclined to the view that maybe, perhaps, the US government should inch toward the legal standard on prosecution of torturers required of it by a law signed by Ronald Reagan, not to mention the Geneva Conventions.

With their drive for impeachment, the Republicans dominated the headlines and all but paralyzed the Clinton White House for two years. Now it should be payback time. Obama’s pledge to the American people: Cheney and Bush behind bars by 2012, plus Gonzales, Yoo, Addington and the rest of the pack. We crave drama. From Obama we’re not getting it, except in the form of racist rallies. This is his last, best chance.