For decades Republicans promised voters that they would reduce the size and power of government if only they controlled the White House … if only they controlled the Senate … if only they controlled the entire government. Beginning in 2001, they did.

And instead of smaller government, Republicans delivered a trillion dollars in new federal spending, exploding earmarks, massive new entitlements, expanded federal control over schools and marriage, and a surge in executive power.

So how will President Obama and the Democrats govern?

Prediction: Despite conservative fears, they won’t move left enough to satisfy the bloggers, activists and permanent protesters who have been driven mad by the outrages of the Bush administration.

And they can’t possibly satisfy the dewy-eyed dreamers who think Obama will transcend race and party and region and bring us all together to sing Kumbaya. The journalists who get chills when he speaks will likely discover that he is a young and inexperienced president facing difficult domestic and international problems that don’t easily yield to eloquence.

Meanwhile, Democrats in control of the White House and both houses of Congress for the first time since 1994 will likely try to move even further left than Bill and Hillary Clinton did after the 1992 election. Despite President Bush’s trillion-dollar increase in federal spending (even before the financial bailouts), the Democrats have another trillion dollars’ worth of spending plans. At a time of economic weakness, they intend to raise taxes. They will push for a global-warming bill, even though any policy that could actually reduce warming would be so unbelievably expensive that even pumped-up Democrats will likely settle for a symbolic bill. (Thus angering the angry Left and the Al Gore faction.) Powerful House Democrats want to eliminate the 401(k) retirement system and force everyone into a government retirement plan.

Like the Clintons, Obama and his congressional colleagues will want to move quickly toward national health care. That idea is popular on the campaign trail, but it may become less so when Congress begins to debate the details of bringing 50 million more people into a government program, controlling private health insurance plans and restricting many people’s choice of a doctor. It could be another HillaryCare debacle.

The victorious Democrats may also try to lock in their majority status through such measures as “card check” legislation, which would abolish secret ballot elections in determining whether employees are represented by unions, and a revival of the so-called Fairness Doctrine to shut down conservative talk radio, which played such a key role in drumming up opposition to the Clinton administration.

In fact, Obama’s first two years might end up sharing something very big with Clinton’s. Believing that his election was not just a rejection of the Bush administration’s failures but an affirmative endorsement of the liberal Democratic agenda, Obama might very well move too far left and create a Republican renaissance.

HillaryCare and other liberal policies turned Congress over to the Republicans in 1994; ObamaCare, tax hikes, out-of-control federal spending, and the other policies on the Pelosi-Reid agenda might do it again. The 2010 election could be a lot more fun for Republicans with Obama in the White House than it would have been with McCain there.

Of course, the economy often plays a role in elections. How strong will the economy be in the fall of 2010? Well, if Obama keeps bailing out industry after industry, raises taxes, and even threatens costly regulations on energy and finance, the economy is not likely to get any stronger. If that happens, the odds of another 1994 are high.

But business cycles, as they say, are cycles. There’s a good chance that we’re in a recession now and that we’ll be in a recovery in 18 months. The U.S. economy has a great deal of underlying strength; fundamentals are indeed strong, as Obama ridiculed McCain for saying, and it may be able to recover from the housing bust fairly soon. Some economists say investors are already driving stock prices down in anticipation of Democratic control of the federal government, so that bad Democratic policies won’t push the market down much further.

But the economy was in fairly good shape in 1994. Leading political scientist Walter Dean Burnham noted after the 1994 election that most elections in which the president’s party lost at least 40 House seats were marked by an economic slump, but that was not the case in 1994. Even a strong economy might not save a party that pushed a strongly left-liberal agenda in a country that still believes in economic individualism.

Three or five years from now, small-government Republicans may look back and realize that the defeat of a second consecutive big-government Republican by a bigger-government Democrat was just what the Republican Party needed to rediscover its roots and come back fighting.