By MAUREEN DOWD

As soon as I started covering Barack Obama, I knew he was going to be trouble.

Not Global Trouble, like W. and Dick Cheney. Or Hanky-Panky Trouble, like Bill Clinton and John Edwards. Or Tedious Trouble, like John Kerry and Michael Dukakis.

He was going to be the kind of guy who whipped you up and then, when you were all excited, left you flat, and then, when you were deflated and exasperated and time was running out, ensorcelled you again with some sparkly fairy dust.

It’s an irritating pattern. Not as puerile as Bill Clinton’s pattern of wasting time and plunging into personal chaos, or as horrifying as Dick Cheney’s routine of bullying and cutting paper dolls out of the Constitution.

But not as reliably uplifting as Jed Bartlet either.

After keeping his great powers of persuasion and elucidation under wraps all summer, the president at long last comes forward to explain his health care plan to an utterly confused and increasingly skeptical and wary public.

He should have done this speech back in June and conjured up a better glossary. You can’t combat a scintillating term like “death panels” with a somnambulant one like “public option.”

President Obama is so wrapped up in his desire to be a different, more conciliatory, beer-summit kind of leader, he ignores some verities.

Sometimes, when you’ve got the mojo, you have to keep your foot on your opponent’s neck. When you’re trying to get a Sisyphean agenda passed, it’s good if people in the way — including rebellious elements in your own party — fear you.

Civil discourse is fine, but when the other side is fighting dirty, you should get angry. Don’t let the bully kick sand in your face. The White House should have impaled death panel malarkey as soon as it came up.

By the time the president got feisty in a speech on Monday, the inmates had taken over cable TV, much like the spooky spirits swarming up over Bald Mountain in “Fantasia.”

Even Steve Hildebrand, the strategist who helped shape Obama’s historic win in the Iowa caucuses, complains that his former hero “needs to be more bold in his leadership.” Disenchanted at Obama’s disengaged approach on health care and gay rights, Hildebrand told Politico’s Ben Smith that he was “losing patience.”

It was one thing for Obama to delegate freely when he was on the Harvard Law Review, but it’s madness to go play golf and delegate freely to Congress, letting Nancy Pelosi make your case. After signaling that there was nothing he’d fall on his sword for on health care; after dropping Van Jones at the first objection from Glenn Beck — a demagoon who called Obama a “racist” — the president is getting to be seen as an easy mark.

If Obama didn’t have a knife-thrower like Rahmbo in the Oval, Democrats would be totally convinced that the president would fold in a heartbeat.

In the absence of more vivid presidential leadership, the Democrats have reverted to their old DNA — self-destructive scrapping and spending. And the Republicans are sticking to theirs — being mean-spirited and shameless, attacking big government spending while taking no blame for their own.

Just as he let Hillary breathe new life into her faltering campaign in New Hampshire, Obama let the moribund Republicans revivify themselves in the slashing image of Limbaugh and Palin. Administration officials have been chortling that Republicans overreached in criticizing the president for giving a speech urging kids to study hard, write their own destiny and wash their hands.

It’s true that Republicans who objected looked risible. On MSNBC, Joe Watkins, a G.O.P. strategist, explained the perils of letting “one of the most gifted speakers that the world has ever seen” speak to impressionable children.

What if next time, he asked, the president made a strong argument to kids about the Defense of Marriage Act? “What if,” he wondered, “kids come back home and say to their mom and dad, when the president who they like and who they agree with, tells them marriage is not necessarily between a man and a woman?”

But if such Republicans seem loco, and the far left looks easily outmaneuvered, the president seems lame, too, for letting the crazies and uglies get on offense all summer, showcased by a superficial media beast. Laura Bush had to ride to Obama’s rescue and explain that he wasn’t a brain-washing alien, that it was a good thing for a president to inspire kids.

It shouldn’t take a superhuman effort by the Democrats, with an assist from a Republican former first lady, to beat back the most obviously nutty, stupid things that Republicans say.

The president told students on Tuesday that “being successful is hard” and “you won’t necessarily succeed at everything the first time you try.”

He should take his own words to heart. He can live long and prosper by being less Spocky and more Rocky.