The Republican Convention ended on the theme “Believe in America.” That sounded nice, but it was just another platitude. Mitt Romney's speech was filled with platitudes: “We will honor America's democratic ideals. ... We're united to preserve liberty.”

Please.

Liberals and conservatives have real differences. We should state them.

America is going broke, and tough decisions must be made. To save our future, we must slow the growth of entitlements and military spending. Mitt Romney was silent about that.

Sure, “Believing in America” means individuals get to decide how to run the businesses we create. But it should also mean that we get to run the rest of our lives, too: whom we marry, what we do for recreation, what substances we ingest, how big our soft drinks are. Mitt Romney said nothing about that.

I want to believe that if Romney is elected, he will finally impose some fiscal discipline and fight to put America on a sustainable course — but his Tampa speech gave me no confidence that he would.

Instead, he pandered, saying, “As governor of Massachusetts, I chose a woman lieutenant governor, a woman chief of staff, half of my cabinet and senior officials. ...”

So what? What does that have to do with America's problems? Was that supposed to persuade people that Republicans don't wage “war on women”? It won't.

If conventions are mere infomercials, Republicans should at least do them well.

It's offensive that politicians force taxpayers to pay $18.3 million to subsidize these pep rallies. Sen. Tom Coburn, R-Okla., tried to end the subsidies, saying, “There is no justification for spending public funds on booze, balloons and confetti.” He's right. But Congress ignored him.

The Republicans did some good things in Tampa, like showing two debt clocks and allowing speakers like Ted Cruz to say, “Rights are secure only when government power is restrained.” But then Mitt Romney spoke. He said nothing of significance.

“Believing in America” means objecting when politicians claim they solve our problems. Romney said he has a “plan to create 12 million jobs.” Huh? Why not 13 million? Why not 50? Promising 12 million is an absurd conceit. When politicians say, “Yes, we can,” we should say: No, they can't! Government fails, but individuals succeed.

The Dems are worse. What do they stand for? They say they believe in a progressive, liberal society, but to them that means a giant government that pretends to solve problems, causes new ones and then spends even more to appear to solve those problems.

I say “appear” because they never actually do it.

President Obama came in full of promises. What's he accomplished? He expanded George W. Bush's dangerous debt. Government spending sets peacetime records. He proposed nothing serious to bring Medicare under control. He didn't curtail our role as world policeman — on the contrary, the administration routinely bombs several populations by remote control. Military spending continues to grow.

Here's what I wish Obama would say:

“I was wrong to expand government the way I have. I overreached. Modern liberalism put us on an unsustainable course. I will save America by restoring limited government that keeps the peace but then leaves free people alone.”

Hey, I can hope.

Mr. President, like you, I believe in social justice. But I believe in Thomas Jefferson's idea of social justice: a free society where people are unimpeded by bureaucrats and politicians; where people freely trade goods and services — that is, cooperate — without anyone telling us what to do.

It means that the government won't engage in what Frederic Bastiat called “legal plunder” — taking resources from some (mostly working people) to bestow them on others.

That's genuine liberalism — original liberalism. You, Mr. President, have bought into the upside-down distortion of liberalism, where government runs things (much of it on behalf of cronies — the well-heeled and well-connected) and the rest of us follow directions.

That's not liberalism. Let's call it what it is: corporatism, state socialism, crony capitalism. Liberalism is about liberty: individual freedom and free markets.

Only that can bring us the real hope and change that freedom represents.

John Stossel is host of “Stossel” on the Fox Business Network. He's the author of “No They Can't: Why Government Fails, but Individuals Succeed.”