It sometimes goes overlooked, but once a presidential candidate wins a party’s presidential nomination, he or she necessarily becomes head of the party. When John McCain became the GOP nominee, he effectively began to call the shots at the RNC. With Barack Obama having secured the Democratic nomination, the DNC is his to do with as he pleases.

Not surprisingly, with a compressed general-election calendar, Obama’s campaign isn’t wasting any time. This morning, Obama strategist Paul Tewes took up residence at the DNC, brought in to “help manage the transition as the DNC swings into action on behalf of Obama’s general election candidacy, and to help oversee fundraising and other political matters.” Also this morning, on Obama’s instructions, the DNC announced it will no longer accept contributions from federal lobbyists or political action committees, which is consistent with the fundraising guidelines his own campaign follows.

But what about Howard Dean? It wouldn’t be at all unusual for the Democratic nominee to thank the current DNC chair for his hard work, pat him on the back, and offer him a lovely parting gift, while installing a close candidate ally who would make the DNC an extension of the nominee’s campaign. Indeed, that would generally be the norm at this point in the process.

I’m pleased to report, however, that Dean is staying put.

The Obama campaign confirmed today that Howard Dean will remain chairman of the Democratic National Committee, even as Obama puts his own stamp on the DNC.

“Sen. Obama appreciates the hard work that Chairman Dean has done to grow our party at the grass-roots level and looks forward to working with him as the chairman of the Democratic Party as we go forward,” Obama spokesman Bill Burton said.

Dean has shed his lightning rod status in recent years and focused more heavily on building state party organizations — a mission that gave him a base of support in the states and that matches Obama’s plan to use his resources to keep McCain on the defensive in a wide range of states.

Good. With Dean staying right where he is, Dems are better off.

Interestingly, the announcement about Dean’s continued employment coincides with the requests of state party chairs, who’ve grown quite fond of Dean’s bottom-up philosophy. From a report this morning, before the announcement was made:

Obama also likes control, and though Dean has generally avoided being a distraction, he’s not Obama’s guy.

But Dean also has a new base: The state party officials who love his 50 state program, which has given them cash and paid for something like 200 field organizers around the country. They want Dean to stay, and will fight to keep him.

“The Obama campaign is aware of the affection that many state chairs have for Governor Dean,” Brian Melendez, the Minnesota Democratic chairman told me the other day.

Melendez also said he wasn’t sure Dean would want to stay, but he and other chairs would clearly like him to.

Now, everybody’s happy.

It’s worth noting, from time to time, that Dean has been a real success story at the DNC. His 50-state strategy was extremely controversial with the party establishment, and leaders on the Hill have always kept Dean at arm’s length — while keeping a quizzical eye on him.

But Dean’s efforts paid huge dividends in 2006, and he’s well positioned to deliver again in 2008. That the Obama campaign appreciates this is a very good sign.