WASHINGTON - President Obama’s promised jobs plan needs to be unrealistic and unreasonable, at the very least. If he can crank it all the way up to unimaginable, that would be even better.This is a moment for the president to suppress his reflex for pre-emptive compromise. The unemployment crisis is so deep and self-perpetuating that only a big, surprising, over-the-top jobs initiative could have real impact. Boldness will serve the nation well and, coincidentally, boost Obama’s re-election prospects.The political calculus is pretty simple. If voters base their decision on the state of the economy on Election Day, Obama is in trouble. Even the most optimistic scenarios predict that unemployment will still be above eight percent next fall. These rosy projections envision month after month of painfully slow growth, the kind that is barely discernible. Pessimists see another dip into recession.Note that I said this would mean Obama is in trouble, not that he’s toast. Pay no attention to the sage analysts who furrow their brows and note that no president since Second World War has been re-elected with unemployment above 7.2 percent. This figure is arbitrary and meaningless. Before Ronald Reagan won his second term in 1984, those same analysts would have sniffed that no post-war president had been re-elected with the unemployment rate above six percent. Reagan won 49 states.And why does the furrowed-brow crowd insist on limiting the sample to presidents of the post-Second World War era? Perhaps because Franklin Delano Roosevelt totally messes up the storyline. FDR was re-elected in 1936 when unemployment was roughly 17 percent. Voters understood they were living through a global economic crisis that wouldn’t be solved overnight.The recent dip in Obama’s approval ratings appears to reflect dissatisfaction with his handling of the economy and points to a potential vulnerability that his Republican opponent will seek to exploit.Obama can quite likely win by convincing voters that even if they’re unhappy with his economic policies, the nation is better off sticking with him because any of the Republican candidates is likely to make things much worse.This line of argument has the benefit of being true. Does Mitt Romney have anything to offer except the warmed-over policies of tax cuts and deregulation that landed us in this mess? How will Rick Perry explain his view that Social Security is an unconstitutional Ponzi scheme? Can Ron Paul convince Americans to carry satchels of gold dust to the mall? Does Michele Bachmann have an economic program at all?Obama can probably win this way, but he wouldn’t enter his second term with much of a mandate. That’s why the FDR example is relevant: Roosevelt won re-election in the midst of the Great Depression not by convincing voters that his opponents would make the economic situation worse but by demonstrating his utter determination to return the nation to prosperity, no matter what obstacles he had to overcome.Obama and his advisers know very well that this is the wrong time to cut government spending. They know that using federal money to seed big new initiatives to upgrade the nation’s crumbling infrastructure, jump-start the “clean” energy industry, retrain the unemployed so they can compete in tomorrow’s job market would give the economy a much-needed boost. They know, too, that federal action to buoy the housing market would help revive consumer spending, thus giving corporations a reason to invest the estimated $1 trillion they’re sitting on.Such ambitious proposals would demonstrate that the president is willing to think big that he is not willing to accept the Republican narrative of massive retrenchment and, by implication, inevitable decline.So Obama should go big, not small, with his jobs plan. It is hard to overstate how apprehensive most Americans are about the future. Boldness from the president may or may not get the nation’s mojo working again. Timidity surely won’t.Republican leaders in the House of Representatives would immediately declare any such ambitious programme dead on arrival. The president should welcome their opposition and campaign vigorously against it. He can offer voters a choice between a pinched, miserly vision of the country’s prospects on the one hand and an optimistic, expansive view on the other. He needs to demand what’s right, not what the other side is willing to give.We know Obama can be rational, realistic and eminently reasonable. Right now, he needs to be anything but.Eugene Robinson’s e-mail address is eugenerobinson@washpost.com.(c) 2011, Washington Post Writers Group