It doesn't happen very often -- maybe every 800,000 years or so, scientists estimate. Changes in the magnetic field cause the earth's poles to flip. Suddenly north and south are reversed.

Something similar has happened in American politics during recent years. Once those of us on the right were said to, in the words of William F. Buckley, "stand athwart history, yelling stop." All the big ideas were supposedly coming from the left -- Social Security, welfare and Medicare, to name a few.

But the poles have flipped. These days it's conservatives who have the ideas. And, in an interesting twist, we're remaking the country by fixing the failed policies of the left.

Begin with Social Security.

If there's one thing that all Americans should be able to agree on, it's that Social Security is in trouble. The Depression-era program is "pay-as-you-go," meaning today's taxpayers fund today's retirees. But we know that, sometime around 2018, we will start paying out more in benefits than we take in through taxes.

Conservatives have an answer: Personal Retirement Accounts. PRAs would allow workers to save a portion of their Social Security payroll taxes in accounts they would control. A study from The Heritage Foundation shows that, over time, even the lowest-paid workers could build up a sizable nest egg for retirement. At the same time, anyone who wanted to remain in the current system could do so, so there's no risk that those near retirement age would lose benefits.

We'll have to pay some transition costs, of course. But since we're running a surplus now, this is the time to act. With each passing year, that surplus gets smaller, the crisis comes closer and the ultimate transition costs get larger. But today's liberal thinkers prefer to ignore the problem. The bottom line is that there are only three ways to preserve Social Security. We can cut benefits, we can raise taxes or we make existing taxes work harder through PRAs.

Some politicians try to deny this, though. They act as if some fine-tuning will fix the problem. Others, such as John Kerry, won't even go this far. Throughout his campaign, Kerry promised he would not raise Social Security taxes, would not raise the retirement age and would not cut benefits for people who rely on Social Security. He also ruled out PRAs, calling them "risky personal investment accounts."

In other words, do nothing. Let the problem get worse and let someone else solve it down the road.

That sounds similar to the way the left wanted to handle welfare reform. Back in the 1960s Lyndon Johnson had a big idea, and liberals ushered in a so-called "great society." Over the next 30 years the federal government poured more than $5 trillion into various programs, without producing a noticeable drop in poverty. In fact, the government was actually rewarding broken homes, illegitimacy and paying people not to work.

But in 1996, conservatives stepped in. Our idea included requiring that welfare recipients actually work or train to work if they wanted to receive a check. In the last eight years, child poverty and dependence have plummeted, and employment among single mothers has skyrocketed.

Today we want to do something similar with Medicare. Last year, Congress passed a massive new prescription-drug entitlement that will take effect in 2006. It's slated to cost more than $43 billion in its first year alone.

But there's a better way: Medicare drug-discount cards. These cards harness the power of the market to allow seniors to save up to 90 percent on their prescriptions. Plus, they do so without the sort of government price-fixing that might limit access to -- or development of -- new drugs.

Liberals opposed the president's plan to add prescription drugs to Medicare -- as many of us did. But they also failed to lay out an alternative, which conservatives did with drug-discount cards.

Conservatives intend to fix Social Security, welfare and Medicare -- the very programs that liberals created. And we'll do so no matter how often the left yells, "Stop!"

Ed Feulner is the president of The Heritage Foundation (heritage.org), a Washington-based public policy research institute.