A troubled economy is always the sitting president’s fault. It was when Ronald Reagan defeated Jimmy Carter, when Bill Clinton defeated George H.W. Bush, and when Barack Obama defeated John McCain by running against George W. Bush.

At about this time in 2008, candidate Obama campaigned against high gas prices, then at $3.50 a gallon, and against high unemployment, then at 5.5 percent, having seen “the greatest rise in more than 20 years.”

Today the average cost for a gallon of gas is $3.94, after dropping to $1.85 prior to Obama’s inauguration. And the unemployment rate is at 8.2 percent. Though this is the lowest rate in three years, the number of Americans working is still below the number working in January 2009.

But in this election year, don’t blame it on Obama. We’re told it’s not his fault. Blame it on Republicans—even though they control only one-half of one-third of the federal government.

Other than war and peace, modern-day elections always turn on the economy. If the economy is good, the incumbent will likely face an easy reelection. If the economy is bad, the advantage should go to the challenger. I say “should” because the challenger’s campaign has to keep the focus slavishly on the economy while the incumbent tries just as furiously to refocus the election elsewhere.

In 1980 Reagan kept the message simple: he would lower taxes, decrease federal spending, and increase domestic energy to reinvigorate the flagging economy. It worked. He won 90.9 percent of the electoral vote.

By 1992, the economy had slowed down. And though Bush 41 was immensely popular after Desert Storm, many voters, especially within his own party, never forgave him for breaking his campaign promise not to raise taxes. A sign was posted in Clinton’s campaign war room: “It’s the Economy, Stupid.” And it was. Bush earned only 37.5 percent of the popular vote, having to battle against the competing economic views of Ross Perot, with 18.9 percent, and Clinton, who won with 43 percent.

Jobs numbers have been looking good for Obama, increasing by more than 200,000 for three straight months prior to stalling in March with only 120,000 jobs added. This creates questions. And Team Obama may also be experiencing this fiscal uncertainty as fundraising for the president reportedly has fallen behind.

While there is debate among economists about the extent and duration of recovery, that is all academic. The changes are not yet felt on Main Street. And in an election year, that’s where it matters most.

The messaging challenge for the Republican Party and its presumptive presidential nominee, Mitt Romney, is to keep the focus on the economy without appearing to talk down the recovery. With the Obama messaging machine gearing up, it also will be a challenge not to get distracted by the many diversions to be thrown.

When the American public is so desperate for good news on the economic front, how does Mitt Romney throw a wet blanket on what appears to be a recovery? How do Romney and the Republicans not appear as if they are rooting for bad news for the next six months? It takes leadership. It takes vision. It takes being bold and telling the truth. It takes laying out a real plan that takes the country past November and well into the future. And it takes articulating change people can believe in.

And it means convincing the American people that getting better is not good enough.

With a troubled economy and wars abroad, the nation reached fatigue in eight years under President Bush. Are we fatigued again in just three years under President Obama?