The Trump tax cuts have opened the biggest breach in two decades among Republicans and Democrats over whether the U.S. tax system is fair — a divide that could shape the outcome of the 2020 elections.

A hoard of Democrats running for the White House advocate higher taxes, with some such as Sens. Bernie Sanders and Elizabeth Warren calling for a wealth tax. Republicans have responded by attacking Democrats as “socialists” whose policies will ruin the economy.

Staunch liberals and conservatives are both driving, and reflecting, the message delivered by party leaders.

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Some 64% of Republicans now say the tax system is very or moderately fair, the highest level since the polling firm Pew Research began keeping track in the late 1990s.

By contrast, a new Pew survey found that only 32% of Democrats view the tax system as fair. That’s the lowest level the firm has recorded.

Nearly three-quarters of Democrats, what’s more, say businesses earn too much profit. Only 38% of Republicans agree.

It wasn’t always that way. Before Trump was elected, partisans on the left and right had a similarly jaundiced view of the U.S. tax code. Gaps between the two parties emerged now and then, but they were never as wide as they are now.

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The 2017 Trump tax cuts have deepened the division. Republicans reduced taxes across the board and instituted the biggest corporate tax cuts in 31 years.

While 71% of Republicans approve of the law, 79% of Democrats disapprove.

Men, older voters and those lacking a college degrees are more likely to favor the Trump tax cuts, but women, younger voters and the college-educated are more likely to be opposed.

Overall, just 36% of voters approve of the law vs. 49% opposed, Pew reported.

A separate poll by the Wall Street Journal/NBC News found that most people don’t really know whether or by how much the tax cuts have affected their tax-home pay.

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Whatever the case, Democrats and Republicans no longer appear to find much common ground.