HOW often should you give a politician the benefit of the doubt—take what he says at face value, trust in the sincerity of his motives, make allowances for the baffling complexities of his predicament? Never, says the jaded half of Lexington's brain. Sometimes, answers the half that still likes words such as hope and change and has a soft spot for Barack Obama. The president brings out this reaction in a lot of people. Polls show that even among voters who loathe his policies a great many continue to admire the qualities of the man himself.

When it comes to the politics of immigration, however, it is getting harder to give Mr Obama the benefit of the doubt. On July 1st he made a big speech on how to reform America's broken immigration system. He laid out the problem at hand with his customary clarity. Thanks to decades of porous borders, some 11m illegal immigrants live in the United States. America cannot give them a blanket amnesty because that would encourage a further surge of illegal immigration. But since they are now woven into the fabric of the nation and its economy, nor can they all be slung out. So what they need is a pathway to legal status: they should register, admit that they broke the law, pay a fine, and taxes, and learn English. “They must get right with the law before they can get in line and earn their citizenship,” said the president.

The only decent solution

This is surely right. America cannot kick out all its illegal immigrants without undertaking one of the biggest forced migrations in history. America could not do such a thing and still be true to itself. Illegal immigrants from Mexico have picked America's fruit, shined America's shoes and sweated in America's workshops; many of their children have grown up to become Americans themselves. That is why Mr Obama's plan is both the only practical and decent plan and, in essence, the same one the Republican administration of George Bush pushed for.

Good speech. Good plan. So why the cynicism? Because making a speech, and having a plan, are not the same as doing something. And Mr Obama does not intend to do anything right now. He is not proposing a particular piece of legislation. At most, his speech is a promissory note, a reminder to America's Hispanic voters that they can at some point count on the Democrats to do the right thing. Hispanics voted in droves for Mr Obama in 2008 but their ardour has cooled: the proportion approving of his performance fell from 69% in January to 57% in May, says Gallup.

Hence, concludes the jaded half of Lexington, Mr Obama is merely pandering to an important segment of his political base. And this comes soon after a cynical manoeuvre by Harry Reid, the Senate majority leader, who in April contrived to give the misleading impression that Congress intended to enact immigration reform before the end of this year. That did not damage Mr Reid's prospects in Nevada, where he faces a desperate battle in November and 25% of the population is Hispanic. But it did damage the Democrats' relations with Senator Lindsey Graham, part of the small band of Republicans in the Senate who are still true believers in comprehensive immigration reform.

Mr Obama's defenders argue that the president cannot match words with deeds at present. As he said in his speech, no law will pass without some Republican support: “That is the political and mathematical reality.” And the Republicans in their present obstructive mood show little appetite for this cause. Even a potential partner such as John McCain, who with the late Ted Kennedy was the brains of the reform efforts of Mr Bush's second term, has bent with the nativist winds as he fights for re-election in Arizona, one of many states in which a moral panic against illegal immigration has taken hold. No Republican votes, no reform bill: you cannot blame Mr Obama for that, can you?

Perhaps you can. Mr Obama is president; he chooses his own priorities. Had he not promoted health care above immigration, a comprehensive reform might have been put before Congress before the mid-terms made it toxic. But the bigger point is that if he cannot move on what he calls this “moral imperative” this year he must do so in 2011, before the presidential election of the following year casts an equally chilling shadow. That means he should be bending every sinew to preserve relations with the small band of senior Republicans who support the cause and whose co-operation will be no less essential in 2011.

Instead, Mr Obama in his speech and Mr Reid in his stratagem seem to have gone out of their way to inject immigration into the mid-terms and place exclusive blame on the Republicans—even though many Democrats in Congress are no less obstructive. And nothing could be better calculated to alienate potential Republican partners than this week's move by the Department of Justice to invoke the supremacy clause of the constitution to strike down the new law in Arizona that gives the police wider powers to identify illegals. Arizona's law is an abomination, says Tamar Jacoby, president of a pro-reform lobby, ImmigrationWorks, but suing Arizona will baffle and anger the 60% of Americans who say they support it. Only the federal government can fix what is wrong with immigration, she says—but not with a lawsuit.

Senator Graham, Senator McCain and John Kyl, Arizona's junior senator, could form the nucleus of Republican support for a bipartisan reform of immigration next year. In theory, both parties will have an interest in co-operating. Mr Obama needs to redeem his promise to Hispanic voters and Republicans need to restore their standing with a constituency whose power to swing elections grows with every passing year. But Mr Obama has put the noses of those who should be key allies out of joint. The instinct to give him the benefit of the doubt may be understandable. But on this occasion, no need to give the man a break.





Economist.com/blogs/lexington