Two presidents boasted about the strength of the American economy this weekend, each claiming credit for the steady growth and declining unemployment as President Donald Trump seeks to parlay the nation's economic success into a winning midterm message for his embattled party — and former President Barack Obama reminds voters just when the boom began.

"When you hear how great the economy's doing right now, let's just remember when this recovery started,” Obama said on Friday in a speech that marked his first foray into the upcoming elections. "I mean, I'm glad it's continued, but when you hear about this economic miracle that's been going on, when the job numbers come out, monthly job numbers, suddenly Republicans are saying it's a miracle. I have to kind of remind them, actually, those job numbers are the same as they were in 2015 and 2016."

Trump disparaged the speech, at one point saying he fell asleep during it.

“If the Democrats got in with their agenda in November of almost two years ago, instead of having 4.2 up, I believe honestly you'd have 4.2 down,” Trump said Friday night, speaking of GDP growth. “It was the weakest recovery in the history of our country since, I guess, to be totally specific, because I'm not sure they've gone any further, since the Great Depression.”

“The Economy is soooo good, perhaps the best in our country’s history,” Trump wrote on Twitter on Monday.

Earlier this summer, he stood on the South Lawn of the White House and boasted about achieving a "turnaround of historic proportions" — an "economic miracle."

The Economy is soooo good, perhaps the best in our country’s history (remember, it’s the economy stupid!), that the Democrats are flailing & lying like CRAZY! Phony books, articles and T.V. “hits” like no other pol has had to endure-and they are losing big. Very dishonest people! — Donald J. Trump (@realDonaldTrump) September 10, 2018

The economy's success or failure depends on much more than who sits in the Oval Office, but let's take a look at the facts here.

Was the economy struggling when Trump took office?

Absolutely not. Trump inherited a booming economy with low unemployment and steady job growth — an easy win on day one — and he quickly claimed credit. Early in his presidency, Trump boasted about job gains starting from his election onward, crediting Obama's final months as his own.

It is extremely unlikely that the GDP could ever have been negative 4.2 percent no matter who was elected in 2016. At the height of the 2009 recession, GDP was at -2.5 percent. It has not been at or above -4.2 percent in 86 years.

The economy was, however, struggling when Obama took office in 2009. He inherited a dismal economy in the middle of a recession that lasted 18 months, facing what many feared would be a depression, and was able to turn it around in the first years of his presidency. The U.S. is now its 10th year of economic growth, and in its longest period of growth with 95 straight months of job creation. The bulk of that decade of growth was under Obama’s presidency, and can fairly be credited to him.

Still, as Trump accurately points out, the recovery under Obama was marked by a slower rate of growth than what followed previous recessions, such as the recovery under President Ronald Reagan in 1983 and 1984.

But, what about the Trump effect?

Trump's supporters say he's supercharged the economy. Now in the second year of his presidency, he has passed a major tax bill and rolled back a significant number of regulations, giving the economy another injection of capital — though economists disagree on the how much the tax cuts will really benefit the larger economy and whether it will have lasting effects to the economy.

Trump has surely seen some impressive data points in his first term: GDP growth has reached 4.2 percent, unemployment has reached its lowest point in half a century, and the stock market has reached new heights.

The president and his administration have been eager to tout the numbers. Kevin Hassett, chairman of the Council of Economic Advisers, kicked off the White House press briefing on Monday with a slew of charts. He said the growth is not an extension of a trend, but rather a "clear upward trajectory, way above the trend."

Economists aren't buying it: While the tax cuts probably helped inject some cash into the economy — particularly the stock market — the country has largely maintained the growth it saw under Obama.

The numbers Hassett touted, economists said, were cherrypicked to show a trend that economists say they're just not seeing.

"The entire story of claiming some major change in economic activity doesn’t ring true," said Harvard economist Benjamin Friedman. "I think there’s really very little to point to, and you’d have tell some story based on stock market. Any time the story hinges on the stock market, that means an economist is going to be very much on weak ground."

Hassett did correct Trump, who tweeted Monday morning that "the GDP Rate (4.2%) is higher than the Unemployment Rate (3.9%) for the first time in over 100 years!"

Multiple news organizations had fact checked the president's statement earlier in the day, and found "100 years" to be false. This type of relationship between the GDP and the unemployment rate had not happened in 10 years, Hassett confirmed in response to a question from a reporter.

"You'd have to talk to the president about where the number came from, but the correct number is 10 years," Hassett said. Trump has yet to correct his tweet.

Still, it's impossible to tease out Trump's economy from Obama's this early in the former's presidency. GDP last reached 4.2 percent during Obama's second term. And where workers are concerned, Trump's gains do not yet match his predecessor's. Since Trump took office, the country has added 3.58 million jobs, short of the 3.96 million jobs that were added in the final 19 months of Obama's presidency.

Economies do not grow overnight, or turn on a hair with a new presidency. While Obama can look back on his eight years and see his leadership play out, Trump's effect is still not yet known.

"In my view, the [Trump] effects are going to be much longer term — we shouldn't be looking at these indicators right now, which is just kind of a continuation," Harvard economist Marc Melitz said, citing tariffs and renegotiated trade deals as a top concern down the line. "It’s going to generate a lot of instability. Already you can see some of it in terms of higher prices for a lot of materials in the U.S."

Trump has previously said that the U.S. is enjoying the best economy in America’s history — a claim other fact checkers have ruled to be false.

But it certainly is one of the best, as Trump tweeted today — thanks in large part to Obama.