Barack Obama is both the symbol and the messenger of the change underway in American - and, indeed, global - politics and society. This change, put most simply, is the swing to the left in socioeconomic policy that has already begun and that is likely to gather speed quickly, under the impact of the global downturn. In the narrow context of American presidential politics, a shift leftward was always inevitable, given the way the Bush administration indulged in ideological rhetoric, while on its watch the underpinnings of the US economy rapidly eroded - as direct or indirect consequences of its policies. As the debt crisis unfolds, the extent of the accumulated damage is becoming apparent. But the reason why voters consistently place "the economy" at the top of their list of concerns is not because of macroeconomic issues such as the trade deficit, but because of worries about domestic basics - mortgages, food, gas prices and jobs. In this sense, even McCain is - and even Romney probably would have been - a shift to the left. But Obama, as well as Clinton, represent a much more fundamental change of direction. The fact that Obama has been embraced by youngsters, in general, and students, in particular, suggests that this is a change that has been brewing and whose time has now come. The debt crisis has demonstrated the degree to which the economic agenda of the Right has been subverted by greed and overt criminality. However, in the view of a growing and increasingly influential band of economic commentators, it has also demonstrated the degree to which the ideological underpinnings of the right-wing agenda have been revealed to be flawed. As usual, the debate - at both the theoretical and practical policy levels - centers on the role and functioning of markets. The dogmatic Reaganite/Bushite view that markets could, should and would solve almost all problems, if left to their own devices, is being rejected by voters, students and even professional economists - on the grounds that in practice things don't seem to turn out that way. Rather, it seems that the rich get richer and the middle classes stagnate, while the poor get crushed and left behind. The argument about what should happen will no longer carry much weight - a mirror image of the claim that socialism should not be judged on the basis of the Soviet Union, because it was grotesquely distorted there. The free-marketeers are thus now on the defensive and their close association with the Bush administration makes their position far worse than it might otherwise have been. Free trade is perhaps the best example of this: Virtually all economists understand how and why open global markets make everyone better off - and why the nasty protectionism practiced by both the US and the EU subverted the free-trade principles that they pretended to champion. But the ability to explain this distinction between the desirable theory and the rigged practice of trade policy is being steadily eroded by the failure of mainstream politicians to address the latter - opening the way for populist politicians to leverage discontent. A dogmatic approach that leaves the losers from free trade to their own devices, on the grounds that the wider public is benefiting, merely makes the populists' task easier. Obama, however, may not be a mere populist rabble-rouser. In his first detailed policy speech this week, he outlined plans to pour public money into infrastructure expenditure - something the US desperately needs. Nothing better captures the degree to which "the Reagan revolution" has run its course than that the percentage of flights taking off late surged to new records last year, thanks to congested airports - the very place where the revolution itself took off, when he fired all the air traffic controllers in the US. The shift in America will, inevitably, attract much more attention than parallel or similar changes in other countries. But the move is under way across a broad front: Germany is a good example, with ex-Communist elements from the former East now infiltrating the political scene in the western part of the country and forcing the Social Democratic Party to move away from the center, in an attempt to defend its exposed left flank. In Israel, too, there is already ample evidence of a change in public opinion, although the Olmert government has done an excellent job in placating the potentially problematic political parties and factions - Shas, Gil Pensioners, Amir Peretz and co. - by feeding them enough scraps to keep them on board, in the hope and expectation of getting more. But the underlying trend is clear, and it's likely to emerge more forcefully in the course of 2008.