Finally, there is policy. Democrats have indeed moved somewhat to the left over the last few decades, on both social and economic issues. As Lawrence Summers, the former Treasury secretary (and no lefty revolutionary), likes to say, the last 15 years should have nudged open-minded people to the political left: The free market isn’t delivering healthy increases in living standards for most Americans. In response, Democrats are focusing less on Bill Clinton’s old themes, like personal and fiscal responsibility, and more on using the government to help people.

But think about what a truly left-wing agenda would look like: Top tax rates of 70 percent (which we had as recently as 1980) or higher. A generous “universal basic income.” The elimination of employer-provided health insurance, with a system more like Britain’s. These ideas remain limited to the margins. None is likely to happen even if Democrats sweep the elections of 2020.

I’m not suggesting that the party has completely avoided Trump overreaction. In our polarized era, Democrats do sometimes confuse its progressive base with the country as a whole. They are to the left of the American public on immigration policy, for instance.

For the most part, though, the Democratic agenda remains decidedly center-left: Raise taxes on the rich, and use the money to help the middle class and poor. Protect civil rights. Expand educational access. Regulate Wall Street, and fight climate change. Expand health insurance using the current system. And compromise with Republicans when necessary.

The radical agenda is the Republican agenda: Make climate change worse, unlike almost every other conservative party in the world. Aggravate inequality. Sabotage health-insurance markets. Run up the deficit. Steal a Supreme Court seat. Keep dark-skinned citizens from voting. Protect Trump’s lawlessness.

If you consider yourself a moderate — whether you lean slightly right or slightly left — your choice in this year’s midterms is clear.

And if you consider yourself a leftist, I understand you are probably frustrated that the Democrats won’t go further. But look at the big picture. The Democratic Party may not have moved nearly as much as you would like, but the party has moved. It has adjusted its agenda in response to soaring inequality and stagnant living standards.

The one mistake no voter should make is pretending that the two parties are just different versions of the same thing.

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