During the 2008 campaign, President Obama and his rivals for the nomination used to talk a lot about how they were going to rid the world of both Osama bin Laden and the Bush administration’s tax cuts for the wealthy. Turns out that, of the two, Bin Laden was a whole lot easier to kill.

Political Times Matt Bai’s analysis and commentary.

This is a big reason that White House advisers are now saying that the deal they struck with Republicans over the debt ceiling is better than it appears. Built into the architecture of this arcane compromise, Democrats say, is a “secret trigger” — that is, a stealthy way to finally roll back the tax cuts for the affluent (those earning more than $250,000 annually) that are now scheduled to cost, by some estimates, about $1 trillion over the next 10 years.

The thinking behind this secret trigger idea goes like this: First, lawmakers on the so-called supercommittee — think of them kind of like the Hall of Justice heroes, only flabbier and somewhat less diverse — will almost certainly come up short in their effort to agree on how to find roughly $1.5 trillion in additional savings by the end of this year.

If that happens, then Congress, under the terms of this week’s deal, will face another crisis just after the 2012 election. At that point, members will be forced to either make a new deal on spending reductions or face automatic cuts in the military budget and other popular programs.

That’s precisely when the Bush tax cuts will expire, unless Congress acts to renew them. The administration is betting that the economy will be in somewhat better shape by then, making higher taxes on the wealthy more palatable than they were when the two parties had this debate at the end of 2010.

What’s more, the White House assumes that Republicans in Congress won’t possibly be able to argue for another round of draconian spending cuts while at the same time advancing a bill to preserve tax cuts for the affluent. And even if they did, and managed to get it through a Democratic-controlled Senate, the president could veto the bill.

Hence the perfect moment for Democrats to slay what has become the party’s proverbial great white whale. And it might all work out this way — except that there are a few significant reasons to think that it won’t.

For one thing, it should be clear by now that Republicans will happily and without reservation argue both for painful spending cuts and tax breaks for the wealthy, all at the same time. It’s just what they do.

Conservatives have continually argued that tax cuts spur growth and thus create more revenue. It may sound fanciful to most Democrats, but thus far it’s proven to be a pretty tenable position politically, and there’s really no pressing reason for Republicans to abandon it.

Second, even if Republicans are able get legislation through the Democratic-controlled Senate after the election, it’s not at all certain that Mr. Obama would veto a bill to extend the tax cuts, no matter what his aides say now. Should Mr. Obama lose in 2012, he’s not really the kind of guy you would expect to go out in a blaze of glory, waving around a veto pen after the voters have turned him out.

And if Mr. Obama wins re-election, it’s hard to imagine him opening his second term by rushing to raise taxes on the middle class, which is what Republicans would almost certainly force him to do, by including those tax cuts in any legislation he’d be inclined to veto. They might also make the tax cuts part of any new agreement to raise the debt ceiling — which, unfortunately, should be necessary again around the end of 2012.

The point here is this: Democrats should probably stop waiting for this ideal window in which they can raise taxes without anyone really putting up a fight. The whale is never going to just swim up alongside the boat and roll up on its back.

Cutting taxes, as a rule, is easy and relatively risk free. Raising them is hard and takes some combination of courage and salesmanship. This is what George W. Bush and his party understood when they agreed to tax cuts that would eventually “sunset,” as if the sun ever actually sets on tax cuts in Washington.

If Democrats are serious about reversing the policy of the Bush years, then they will probably have to be willing to make a case for eliminating all the tax cuts, not just those for the wealthiest Americans. And they may have to come up with some kind of more comprehensive plan for modernizing the entire tax code, in order to persuade voters that even if some taxes go up, they might still come out ahead.

There’s no trigger, secret or otherwise, that can spare Democrats a titanic clash over taxes. In politics, you can’t get the whale unless you’re ready to face the waves.