Speculation ended yesterday about who would be tapped to lead Democrats in the Obama era when it was announced that Virginia Gov. Tim Kaine had agreed to lead the Democratic National Committee.

Obama himself was reportedly central to the move, stepping in to convince Kaine -- an early and enthusiastic support of Obama -- to take the job.

What does the Kaine pick mean? First and foremost, I think picking the governor of a Southern state that turned blue in 2008 is meant to signal a commitment to the 50-state strategy pioneered by Howard Dean. It also suggests a willingness to fight for battleground Southern states, and an appreciation of the South's strategic role that Obama's cabinet picks did not.

Ideologically, the message is murkier. Progressives grew increasingly disenchanted with Kaine during his tenure as governor. Kaine brought strong progressive credentials to office as a public-interest attorney, but steadily moved to the center once in office. He gave full-throated endorsements of Virginia's gay-marriage ban and the state's anti-labor "right to work" law, and even endorsed Sen. Joe Leiberman for president in 2004. The final nail in the coffin was when Kaine threw his weight behind a widely-criticized new coal-fired power plant in Wise County.

Kaine's supporters chalked these positions up to the compromises required of a Democratic governor in a largely red state. And Kaine could point to some progressive positions, too -- like the decision to restore voting rights to over 3,000 ex-felons, heavily criticized by the right.

Either way, the DNC position has little to do with ideology, although Kaine's centrism clearly gels with the bi-partisan course being charted by the Obama administration (tax cuts, anyone?).

But organizationally, Kaine is also of a mind with Obama and Dean in his commitment to keep expanding the political map for the Democrats, which can only benefit their long-term prospects.