U.S. President Donald Trump inherited the Oval Office at a fortunate time, economically speaking.

Even before he took over in January, the American economy was running on all cylinders, with strong growth in GDP that has gotten even stronger into 2017.

Contrast that with his predecessor Barack Obama, who inherited a jobless rate that had already spiked and was headed toward 10 per cent in the financial crisis, not to mention ballooning deficits.

For Trump, America's relative economic strength is a political opportunity. A strong economy fattens Uncle Sam's wallet a little more, thereby allowing him to push forward his various agenda items, such as fixing America's crumbling infrastructure and his long-promised tax cuts.

The flip side of that positive economic news is that any wobbles from here on out may be laid at his feet. If the U.S. economy has indeed never performed better than it is now, any regression from that could harm him down the line.

To wit, here's three economics scorecards Trump's fond of trumpeting that may well play a much sadder song for him three years from now.

The stock market

Since Trump was elected on November 8th of last year, the Dow Jones Industrial Average has risen 20 per cent, a feat the new president frequently mentions.

But it's a well-worn tenet of stock markets that record runs don't last forever, and many market watchers are starting to think the current bull run is looking a little long in the tooth.

"I suspect we are in the late stages of a long bull market," New York University financial historian Richard Sylla said recently.

"I see parallels with 1987 when the Dow increased by a hundred points every few weeks before crashing on October 19 in the biggest one-day percentage loss ever. Since Trump was elected, we have seen the Dow hit 19, 20, 21 and lately 22 thousand β€” reminiscent of 1987."

What will cause the next downturn is unknown. Some point at a U.S. recession or geo-political events being the catalyst. 

But whether it happens during or after a Trump administration, the rally has to end some day. The current market rally began on March 9th, 2009, making it more than eight years old. If it lasts through all of Trump's first term, it will be the longest in history.

The jobless rate

When Trump took office in January, the U.S. unemployment rate was already at a relatively low 4.8 per cent, less than half of what it was during the darkest days of the 2009 financial crisis.

Since inauguration day, the jobless rate has continued to fall, with the latest reading from July coming in at 4.3 per cent, the lowest since March 2001.

The good news for Trump is it may fall further. Economists at Goldman Sachs say the unemployment rate could drop to as low as 3.8 per cent next year, so jobs are likely the economic footing that Trump is standing most solidly on.

"The unemployment rate has the ability to stay very low for several years ahead," said Frances Donald, senior economist at Manulife Asset Management. "The element of the economy that will look the most favourable over the next several years will be the job market."

The U.S. economy hasn't lost jobs since September of 2010, the longest consecutive period of gains in history. But a lot can change in 3Β½ years.

"The intervention from central banks is extending this economic cycle out significantly. That said, the further we get into the cycle, the higher the odds of a recession occurring, " Donald said. 

"The odds of a recession in 2020 are higher than they are today."

The national debt

When Trump took office, the Congressional Budget Office estimates the U.S. was running an annual deficit of $585 billion. The national debt stood at more than $19 trillion.

On its current path, it's unlikely Trump will face voters for a second term with a national debt lower than when he took over. His own budget proposal almost guarantees this.

According to the non-partisan Congressional Budget Office, Trump's budget would see smaller deficits than its baseline comparisons. But any deficit β€” even a small one β€” will add to the national debt.

By 2020, the final year of Trump's first term, the CBO projects the deficit will be $775 billion, and the national debt will have grown by another $3 trillion by then.

Candidate Trump criticized the debt added during his predecessor's terms. He even went so far as to promise to eliminate the entire national debt in eight years, a promise his own budget director Mick Mulvaney doesn't think is possible.

"It's fairly safe to assume that was hyperbole," Mulvaney said in an interview with CNBC.

"I'm not going to be able to pay off $20 trillion worth of debt in four years. I'd be being dishonest with you if I said that I could."