He was once hailed as the world's greatest celebrity but now the glitter is tarnished and the hero worship is barely anywhere to be found. So this week Barack Obama is going back on the road -- with just five weeks to save his Democratic Party from ignominy in November's midterm elections.

His blitz through four states is no ordinary road trip: this time the President is making a huge effort to re-discover the enthusiasm and the engagement that proved the key to his success in 2008. So there's just one rally, on Tuesday, to students at the University of Wisconsin, and a series of more informal meetings with "ordinary folks" in their own backyards.

This much more populist message aims to hit back at the Republican "Pledge to America" manifesto: and, as White House communications director Dan Pfeiffer put it, to show "why he thinks the direction the Republicans are pushing to go would be irresponsible, would be a mistake".

Instead the President will focus on the middle classes and America's public deficit, insisting it would be totally wrong to cut taxes and return to the Bush-style policies of the past, and what he's calling "the era of recklessness".

But policies aside, this trip is really meant to mark a return to the old-style Obama -- the grassroots community organiser, the one who spectacularly managed to to connect with ordinary people and fire up a political excitement they never knew they had.

It's an effort too to revive that coalition of young people and minorities that didn't just sweep him to power in 2008 -- but also seemed to usher in a completely new kind of politics, a kind based on inclusion and engagement and fuelled by the desire of individuals to make a difference.

And it's an attempt to turn around the political fortunes of the last 18 months, which has seen Obama and the Democrats beset by falling polls and disillusioned voters who simply don't want to turn out. As the Washington Post put it, Obama's much vaunted grassroots network is now "a shadow of its former self".

Latest polls in a number of key battleground states don't look good for the Democrats: as independent voters lean towards the GOP, while young people and minority voters say they're inclined to stay at home. Although "Organising for America" still has paid staffers in 50 states, trying to get out the vote and keep supporters engaged, there's a palpable "enthusiasm gap".

And hence Tuesday's speech to students in Madison -- trying to recapture just a little bit of the old magic -- and trying to get young people excited about politics again. It's being simulcast to 200 other campuses, with other youth events staged elsewhere, so there's no excuse to miss it.

Communications guru David Plouffe -- the man who forged much of the success story of 2008 -- is said to be behind the University of Wisconsin event, followed by three other old style mass political rallies in the run up to election day.

And meeting voters in their backyards is supposed to convince the country their President is not aloof and out of touch with the real problems they're facing in these tough economic times.

But it's all getting rather late for Obama to turn things around. Meantime there are murmurings about the effectiveness of the White House strategy team, who could once do no wrong, and some beleagued Democrats have insisted they don't want the President stumping for them right now, because it might just make things worse. It seems the old adage has never been more true -- the soaring poetry of campaigns is one thing, the complex and nuanced prose of government, quite another.