Karl Rove, the Republican political savant George W. Bush dubbed “Turd Blossom,” has an election-week tradition worthy of his nickname: He dumps a load of manure on the American public and watches to see if it will flower.

Like clockwork, this year’s shipment was delivered via the opinion pages of the Wall Street Journal, which on Thursday published Rove’s prediction that “sometime after the cock crows on the morning of Nov. 7, Mitt Romney will be declared America’s 45th president. Let’s call it 51%-48% with Mr. Romney carrying at least 279 Electoral College votes, probably more.”

Rove may be right — but only in the sense that a stopped clock is right twice a day. Let’s review his previous predictions:

In November 2000, two days before the election, he forecast that Bush would beat Al Gore by six percentage points and win 320 electoral votes; in reality, Bush lost the popular vote and got to 271 electoral votes only because the Supreme Court essentially awarded him Florida’s.

On the eve of the 2004 election, Rove predicted an easy victory for Bush, asserting that he was ahead in eight of 10 battleground states; on Election Day, Bush’s 286 electoral votes were only a slight improvement over 2000.

In the days before the 2006 midterm elections, Rove confidently predicted a “Republican Senate and Republican House”; Democrats took control of both. Even before the Democratic landslide in 2008, Rove saw a path for John McCain to “be America’s 44th president.”

Rove is an easy target because his motive — conveying a false sense of momentum for Republicans — is so transparent. But he has plenty of company among prognosticators who confidently predict that which they cannot possibly know.

There’s Nate Silver, a statistician-blogger at the New York Times, who predicts with scientific precision that President Obama will win 300 electoral votes and beat Romney by two percentage points in the popular vote. He gives Obama a 79 percent likelihood of winning.

I give Silver a 50 percent likelihood of being correct.

The truth is anybody who claims to know what is going to happen on Election Day is making it up and counting on being lucky. For that reason, this has been a humbling election for people who follow politics. We have filled countless hours of airtime and gone through untold gallons of ink over the past six months, but we are essentially where we were when we started: It’s a dead heat, with the likeliest voters appearing to favor the challenger but the battleground states appearing to give a narrow edge to the incumbent.

There have been ups and downs — it appeared that Romney’s campaign was collapsing in September, only for the Obama campaign to swoon after the first presidential debate — but the 48-percent-to-48-percent tie in the Gallup tracking poll this week is basically the same as it was on April 20, when Gallup had Romney with 46 percent and Obama with 45 percent.

Though this outcome is humbling for the pundit class, it’s depressing for the country. It means that Americans remain evenly split, and that, for at least two more years, our government is likely to remain bitterly divided — with neither side able to claim much of a mandate to fix the nation’s problems.

The enduring stalemate also confirms a failure of imagination, and of leadership, in both candidates and both parties. Both men ran timid campaigns, refusing to talk about the tough choices ahead and devoting most of their energies to rallying partisans who already supported them.

Obama’s attempt at outlining a second-term agenda amounted to too little, too late: a 20-page pamphlet full of photos sent to households in swing states in the campaign’s closing days. The content was mostly scaled-back and repackaged ideas from his first term.

This, though unimaginative, was slightly superior to what Romney offered: a five-point set of platitudes and a detail-free pledge to remake the tax code. Even that vague agenda was left in doubt after Romney’s last-minute rush to the middle, disavowing many of the positions he had taken during the campaign. Missing from both candidates’ pseudo-agendas was anything approaching a specific plan to avert a debt crisis.

Had one of the candidates risen above the caution and the timidity and used the election season to build a consensus for a governing mandate, the Election Day forecasts would have been easy to make. And that man would have deserved to win.