I’ve been meaning for some time to write a short post paying a small tribute to the man I believe is one of the least-sung heroes of the Obama campaign: Governor Howard Dean. Today I sat down to do it and realised this is in fact the very day he hands over to successor Tim Kaine.

Look at this display of front pages covering Obama’s inauguration. What words were selected by more newspapers than any others to summarise the new president’s message to the nation? “Hope over fear.”

Sound familiar? It’s because you heard it throughout the spring of 2004. “Hope not fear” was the  primary slogan of Dean’s campaign. After a year of hearing Obama talk about hope, it’s easy to forget just how radical-sounding this was. In 2004, fear was everywhere in America. Citizens, prodded by regular government threat alerts, feared terrorist attacks. Families feared for their sons and daughters in Iraq, which was just beginning to look insoluble. And the Democractic party feared to attack the war, or President Bush, for fear of sounding weak and unpatriotic. But Dean attacked the war. Dean attacked Bush. And Dean talked unashamedly, unapologetically, about hope.

Dean’s campaign may have failed, and probably rightly. But it provided the first shot of adrenalin that re-started the beating heart of the Democratic party: the grass-roots organisers and volunteers whose energy, four years later, propelled Obama to the nomination and, ultimately, the White House. As the first real internet candidate, Dean laid the groundwork for Obama’s breathaking fundraising organisation. As the first major-party electoral candidate to run against the war in Iraq, he helped set in motion the tectonic shift in public opinion that doomed Clinton and made Obama the Democratic front-runner. And by daring to offer full-throated criticism of President Bush, at a time when the party leadership was too craven to do so, he began the process of breaking down the post-9/11 conspiracy of silence that allowed so many disastrous missteps - Iraq, torture, wiretapping - to happen unchecked.

That same party leadership fought hard to prevent Dean becoming DNC Chair. But, as the grassroots predicted, his leadership was a revelation, galvanising volunteers and transforming fundraising. The 2006 mid-term victories that began the tide that swept Obama to the Presidency? Down in no small part to the smarts and passion of Dean. And that “50-state” strategy that enabled Obama to redraw the electoral map and end, in a stroke, a thousand hand-wringing worries about “divided America”? The brainchild of Howard Dean.

As a presidential candidate, Dean was a failure. But in both that role and his role as DNC Chair, he helped re-inspire a party slouched in despondency - and in his unapologetic passion for progressive politics, he helped Obama re-inspire a nation.