How dumb can you get?

Very (expletive) dumb, to use the vernacular favored by newly indicted Illinois Gov. Rod R. Blagojevich. With obscenity-laden bravado, Blagojevich continued to discuss new corruption schemes on his bugged phone long after receiving clear signs that he was under FBI investigation.

And how venal can you get? Apparently, very (expletive) venal. Telling cronies that he was financially strapped and tired of being governor, Blagojevich allegedly sought to get a lucrative union sinecure created for himself in exchange for political favors, held up funds for a hospital to extract contributions from its executives, wondered if he could foist his equally foul-mouthed wife onto high-paying corporate boards and tried to sell to the highest bidder the Senate seat just vacated by President-elect Barack Obama.

Blagojevich's dramatic downfall is the first big Democratic scandal story of the Obama era. Granted, Obama has yet to set foot in the Oval Office (although right now he's probably wishing that his transition headquarters wasn't in Chicago). But there was no way for Obama to completely avoid comment on a scandal involving the Democratic governor of his home state — especially when Blagojevich's downfall was integrally related to his illegal efforts to profit from Obama's success.

That's not to say that the Blagojevich scandal will hurt Obama. Based on the documents released so far, Obama is looking better than ever. In fact, it was Blagojevich's inability to corrupt the Obama camp that drove the doomed and frustrated governor to a new obscenities-per-minute record. Blagojevich saw his gubernatorial right to appoint Obama's Senate successor as an opportunity that was "(expletive) golden": A Senate seat is "a (expletive) valuable thing," he explained to an adviser.

And he was willing to appoint someone he imagined Obama might favor, but only if he got something lucrative in return. "I'm just not giving (the Senate seat) up for (expletive) nothing." Yet Obama, to Blagojevich's astonishment, expected him to do just that.

When Blagojevich realized that Obama wouldn't "pay to play," he told aides he wouldn't just "suck it up" and give this "mother-(expletive)" — the president-elect — "his senator. (Expletive) him. For nothing? (Expletive) him."

Given the context, Obama should consider it something of an honor to be called an obscene name by Blagojevich.

All the same, Blagojevich's downfall should be a cautionary tale for Democrats still basking in the reflected glory of Obama's win — powerful Democrats aren't immune to human weaknesses.

Idiocy and greed aren't just for Republicans. For every Larry Craig, there's an Eliot Spitzer; for every Ted Stevens, there's a Rod Blagojevich.

In our heads, we Democrats know that. It's just that in our hearts, we don't want to believe it. Because we're the good guys, right? When you're in the opposition, you're already down and out, so what difference does it make if your side's idiocy leaves you — temporarily — a little bit more down and out? And being in the opposition offers fewer patronage opportunities.

But power really does corrupt.

I'm not predicting a rash of new Blagojevich-type scandals plaguing the new administration. The Obama transition team already has issued unusually stringent ethics rules, and Obama's track record of supporting tough ethics legislation (including an Illinois state ethics law) suggests that he'll continue such efforts as president.

But illegal corruption isn't the only thing Democrats should be on guard against. Gaining political power also corrupts in far more subtle ways.

Members of political majorities succumb easily to smugness and complacency, to the conviction that explaining and justifying ideas is no longer necessary, to the temptation to dismiss critics as so many irrelevant cranks. "Groupthink" is mainly a disease of the powerful and complacent, not the fractious opposition.

Never mind Blagojevich. Majorities can get very dumb indeed — and what the new Democratic majority most needs to resist are those more subtle forms of intellectual and moral laziness and corruption. For in the end, arrogance and groupthink can prove far more lethal than even the most scandalous financial shenanigans.

Just ask the thousands dead in Iraq.

Rosa Brooks is a professor at the Georgetown University Law Center. She wrote this commentary for the Los Angeles Times.