Illustration by Kevin Kallaugher

THE reaction to Jesse Helms's death on July 4th is a reminder of how bipolar American politics has become. The right praised him as a man of principle who also overflowed with the milk of human kindness. The left retorted—rightly, in our view—that he was also a bigot and a bully (see article). But at least conservatives and liberals have discovered one thing they can agree on: that Barack Obama is a cynical opportunist, a flip-flopper and a shape-changer, a man who brushes aside his principles with the same nonchalance that lesser mortals reserve for their dandruff.

Bob Herbert of the New York Times worries that Mr Obama is “not just tacking gently to the centre. He's lurching right when it suits him, and he's zigging with the kind of reckless abandon that's guaranteed to cause disillusion, if not whiplash.” Some 22,000 people have protested on his website about his change of heart on wiretapping. A group called “Recreate68” promises to complain about his move to the centre at the Democratic convention in Denver in August.

For its part, the right has discovered that Mr Obama is not a “hard left” liberal, as it had previously thought, but a standard-issue politician who will “say and do anything to get elected”. Charles Krauthammer calls him a “man of seasonal principles”. Bo Snerdley, Rush Limbaugh's sidekick, describes him as “the first black Clinton”. “Has there ever in recent political memory been so much calculation and bad faith by a politician who has made so much of eschewing both?”, asks Rich Lowry, the editor of the National Review.

This is all overstated. Mr Obama was always clear that he was running for the presidency of the United States, not the chairmanship of MoveOn.org. He has repeatedly presented himself as a post-partisan problem-solver who wants to work with Republicans as well as Democrats. His enthusiasm for “faith-based” social services is long held. Even on the issue that first endeared him to the left—the Iraq war—he made it abundantly clear that he was opposed to that particular war, not to the exercise of American power. Still, there is no doubt that he has engaged in a bit of vigorous repositioning in the past few weeks.

The old Obama pledged to take public financing in the general election. The new one will spend what it takes. The old Obama pledged to filibuster a bill giving legal immunity to telecoms companies that co-operated with the government on terrorist surveillance. The new one supports the bill. The old Obama failed to wear a flag pin. The new Obama talks about patriotism in a sea of American flags, praises General David Petraeus, the chief commander in Iraq, raises doubts about partial-birth abortion, agrees with the Supreme Court on gun rights, supports the death penalty for child-rapists and embraces faith-based social work.

But isn't moving to the centre just sensible politics as the primary turns into a general election? Ronald Reagan devoted a great deal of energy to persuading people that he was not a trigger-happy ideologue. Bill Clinton sold himself as a New Democrat who felt Middle America's pain. George Bush initially styled himself a “compassionate conservative”. The likes of Walter Mondale and Michael Dukakis, on the left, and Barry Goldwater, on the right, may have won brownie points from their supporters for sticking to their principles. But they went down to calamitous defeats. The oddity of this election cycle is not that Mr Obama is moving to the centre but that John McCain is moving to the right.

Mr Obama's flip-flop on public finance is certainly cynical (and his willingness to justify it as an act of high principle even more so). But polls suggest that Americans are happy with a certain amount of flip-flopping: Mr Bush has all but destroyed the market in stubborn consistency. And Mr Obama's hard-edged cynicism also helps to quell one of the biggest doubts about his candidacy—that he is too naive and soft-minded to hold the most powerful job in the world.

Mr Obama is capitalising not only on his huge fund-raising advantage over Mr McCain but also on his rival's problems with his base. He is occupying the middle ground in order to reassure white voters that he shares their values. This is no airy-fairy liberal who is going to allow himself to be pushed around by Middle Eastern despots. This is a shrewd opportunist at work.

John Kerry's shadow

The vital question is not whether Mr Obama is changing his positions but whether he is changing them for better or worse. Here the picture is largely positive. His new-found enthusiasm for NAFTA and free trade could help to avert a prosperity-destroying drift to protectionism. Indeed, his chief economics adviser, Jason Furman, sounds like the very model of good sense. Mr Obama's willingness to support wiretapping in certain circumstances suggests that he is trying to strike a balance between security and privacy in what he calls a “dangerous world”: the policy challenge is not to pursue vendettas against the Bush administration but to find a reasonable set of rules to govern surveillance. His repositioning on the Iraq war represents a recognition that the situation on the ground in Iraq has changed dramatically.

If there is a problem with all this repositioning, it is that it is not going far enough for most American moderates. Mr Obama has punted on partial-birth abortion rather than denouncing the whole gruesome procedure. He has insisted on putting restrictions on faith-based social services that most churches find unacceptable. On July 3rd he held not one but two press conferences on Iraq—one in which he seemed to suggest that he would adjust his policy in the light of new realities, another in which he insisted that his position “has not changed”. Mr Obama needs to embrace centrism as a matter of conviction rather than flirting with it as an instrument of political expediency. Otherwise the accusations of flip-flopping that did John Kerry so much harm in 2004 will begin to bite.