Over a decade since the Great Recession, the U.S. economy seems to be on a roll: Wage growth is relatively high, inflation is low, unemployment is really low, and the stock market is booming. Despite President Trump's impeachment — not to mention his erratic, bullying, bigoted behavior — could the economy nonetheless hand him a second term in 2020?

It's definitely a possibility. In fact, a number of observers who run models of elections are already predicting Trump will take home the win. But nothing is certain, and such predictions hinge on the crucial assumption that economic indicators mean the same thing today that they meant one or two or three or more decades ago.

For a long time now, political science has recognized that the performance of the economy — especially its performance in the year before an election — has a very strong influence on how things shake out. Trump may well prove the exception, given both his outlandish personal characteristics, and the fact that he's now only the third president to ever actually be impeached by the House of Representatives. But an upward trending economy tends to mean victory for the incumbent, while an economy on the downturn tends to mean the challenger will win.

Yale University professor Ray Fair, Oxford Economics Ltd., and Moody's Analytics Inc. are all outfits that run election prediction models, for instance. They don't rely solely on the economy. But factors like GDP growth trends, inflation, and the unemployment rate play big roles in their projections. Bloomberg spoke to all three recently, and they were all predicting re-election for the White House's current occupant. "The election is Trump's to lose," Mark Zandi, the chief economist at Moody's Analytics, bluntly put it. "Trump wins if the economy and his approval rating are about the same a year from now as today, and turnout is typical." Moody's has accurately called every election over the last two decades except for 2016. Oxford got 16 of the last 18 elections right.

Granted, these predictions all come with some caveats. But if you dig down into the nitty-gritty of economic data, below the headline numbers like unemployment and GDP growth, there are other positive signs for Trump. While wage growth overall remains somewhat sluggish compared to previous times when unemployment got this low, wage growth for low earners specifically has picked up in the last year or two. Poorer Americans are now seeing their incomes grow as fast as they did in the peak of the last recovery, just before the 2008 collapse. African-Americans and Hispanic Americans are enjoying record low unemployment rates.

Crazy as it may sound to many liberals, the Trump campaign thinks it can pick up some more votes among these minority groups. They don't think they can flip all that many. But Trump's team is basically aiming to replay his 2016 win, where he prevails despite his low approval ratings by holding key Rust Belt and battleground states, and thus keeps an edge in the Electoral College. Flipping even a modest number of minority voters in those states would definitely shore up the strategy's chances of success.

Yet there are other complications that push in the opposite direction.

For instance, in the last year, the economic situation in states like Pennsylvania, Wisconsin, and Michigan has taken a downturn. After a job boom in 2017 and 2018, the manufacturing sector reversed course, and has now bled out nearly all the jobs it gained since Trump entered office. Counties in the Midwest that switched their votes from President Obama in 2012 to Trump in 2016 have lost jobs in retail, mining, and natural resources, as well as manufacturing, and some of their unemployment rates have begun to inch back up.

That's a bad sign for Trump's strategy of holding his own in those crucial states. It's worth noting that many of these same communities were in something of a mini-recession in the runup to 2016 as well. As I said, economic conditions that are heading down tend to favor the challenger, and that probably goes a long way towards explaining why the Democrats' "blue wall" collapsed in 2016. In between 2016 and the last year, those areas enjoyed a rebound. It's just now they look like they're reversing course again.

Recent polling of battleground states found voters' satisfaction with their economic situation dropping, while they've gone from approving of Trump's handling of the economy by a net of 10 percentage points, to approving and disapproving in equal measure. If the slump continues for the next year, Trump will be the incumbent who likely pays the price.

It's also worth keeping in mind the guesswork behind models that look at things like GDP growth and the unemployment rate to predict election outcomes. The implicit assumption here is that the benefits of growing GDP or low unemployment are broadly shared across American society — and thus will reliably lift voters' moods across a wide swath of areas.

But that assumption is looking more and more rickety. Rising inequality inherently means that the same amount of GDP growth benefits fewer people. In the broader context, the recent uptick in wage growth is a minor shift in a decades-long trend of stagnating wages. Over the same time period, costs for things like housing, health care and child care have risen significantly. Meaning we actually need a much longer burst of high wage growth today for Americans to reach the same level of financial security they had during, say, the late 1990s boom. The unemployment rate also has problems, and other indicators suggest that low unemployment rates are less indicative today of the true health of the labor market than they were two decades ago. Finally, real GDP growth, while it's positive, is significantly slower today than it was two decades back in the 1990s, never mind in the 1960s.

Americans feel all this, too. According to recent polling, two thirds of voters think the economy is helping the rich; but only a third say it's helping the middle class, and even fewer say it's helping the poor.

What all this means, ultimately, is not necessarily that the economy is actually bad news for Trump. It simply might be less good news than it first appears. The election is still almost a year out, and a lot could happen in both directions. Despite his low popularity, Trump's job approval on the economy specifically remains 52 percent.

The president still has plenty of routes to victory.

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