In the early 1990s, few right-wing bugaboos loomed as large as Hillary Clinton's secret health-care task force. Conservatives who still routinely invoke the task force can seem obsessed with rehashing the greatest anti-Clinton hits of yore. But look who's talking about the task force now.

"They took all their people and all their experts into a room, and then they closed the door, and they tried to design the plan in isolation from the American people," said no, not Rush Limbaugh or Newt Gingrich or Rudy Giuliani, but the nation's foremost liberal tribune of hopefulness, Barack Obama.

The latest turn in the Democratic primary race is the best thing to happen to Republicans since the 2006 elections. Two high-profile Democrats, Obama and John Edwards, are validating a core part of the anti-Hillary case that Republicans have made for years -- that she's a slippery cynic who cares only about power.

In the initial phase of the Democratic primary fight, her opponents attacked Hillary for voting for the Iraq War and refusing to apologize for it. This was an ideological attack that Hillary cleverly defused, while remaining more hawkish -- and therefore better positioned for a general election -- than her opponents. To the extent such attacks from the left make her seem more centrist, they help her. The latest round of criticisms is more insidious. They aren't so much ideological -- though they still come from the left -- as character-ological. Hillary is a calculating and poll-driven double-talker. This line of attack amounts to millions of dollars' worth of free advertising for the eventual Republican nominee and for conservative groups that will attack Hillary on these grounds next fall.

The character attacks box Hillary in. Her primary strategy so far has been to placate the left of her party while not saying anything that will hurt her in the general election. The strategy involves careful positioning that necessarily opens her to the charges that she's calculating and evasive. Hillary has a bitter choice: either to hew to her (otherwise sensible) primary strategy and get tagged as a shrewish triangulator, or to swing left and risk alienating general-election voters.

This dilemma hung her up on the issue of driver's licenses for illegal aliens. In the infamous Philadelphia debate, she wanted to sound favorable to the licenses to avoid offending Hispanics, but not endorse them. Under the full-on character assault of the debate and afterward, this straddle couldn't be sustained. She went left and came out in favor of the licenses; then, realizing the general-election vulnerability, she reversed course again and opposed them outright ("flip-flopping cubed," said the Chris Dodd campaign).

How can Hillary escape the trap? She probably can never convince people that she's a straightforward politician of courage, but she certainly can convince them that John Edwards is a fraud and that Barack Obama has no experience, no accomplishments and no defining issues, beyond his vaporous abstractions.

This negative strategy, too, has costs. If you didn't like Hillary when she was pretending to be pleasant, just wait until she takes the bark off the first African-American ever to have a plausible chance of becoming president. The good news for Hillary is that the Clinton team excels at demolition jobs -- congratulations, Mr. Obama, you might have just become the Ken Starr of 2007.

The hit against Hillary as a triangulator wouldn't have as much punch if her husband hadn't lived off poll-driven, situational politics for eight years. In a general election, a key point of thematic contention will be whether a Hillary presidency will represent change or -- as Republicans will argue -- an unwelcome return to the 1990s. Here, too, Obama is making the Republicans' case, saying that we shouldn't spend "the next four years refighting the same fights we had in the 1990s."

Hillary now faces the potential of a more drawn-out, and much more damaging, nomination fight than seemed possible even three weeks ago. If Obama needs more material, surely Rush Limbaugh will be eager to provide.