According to Greenberg, "The harder the president bangs these drums, the more Democrats become enraged and a segment of Republicans get demoralized. The more he trashes his Republican opponents in primaries, the more these voters may contemplate different political options."
That is well said. However, the voters Greenberg describes are not "moderates" in the way he wants them to be, and they are a long way from voting for Democrats.
Greenberg does get a lot right about voter dynamics in the Trump era.
The fact is, Trump's actions are met with electric applause in most parts of the Republican Party but with lamenting eye rolls, sighs and gasps in others.
There are some Republicans who Greenberg says are teetering on the edge, unsure of how they will vote if they vote at all in November.
They are Republicans whose temperate approach to politics means they find the president's noise off-putting and discouraging, to say the least.
They find many of his words and actions to be disagreeable, even if they agree with his core objectives.
Most recently, Republicans have objected to separating children from their illegal immigrant mothers at the country's southern border while maintaining support for tougher border security and a crackdown on illegal immigration.
But Greenberg overstates the importance of issues such as abortion and climate change to these voters.
Democrats still don't have a compelling message on the issues that many voters care about most --- starting with the economy and jobs. So why would they make the radical departure from a good and growing Republican economy to a Democratic Party whose only purpose is to "resist" the president?
Greenberg is a pro. He has been around for a long time. He knows Democrats have no economic message.
In a recent op-ed, he warned the Democrats that they will lose their chance to "win landslide victories . . . if they don't address the economic challenges confronting their strongest supporters, who are at risk of staying home on election day."
Greenberg must know the Democrats' lurch to the left turns off broad swaths of the country, many of whom are independent or marginal Republican voters. Their silence is a gift to Republicans.
Not many Republican-leaning voters will want a return to a Democrat-run economy.
When Greenberg tried to explain in his New York Times piece what Republicans turned off by Trump might find appealing about the Democratic Party, all he had were stale platitudes that sounded like classic Hillary-speak.
He described swing voters and disaffected Republicans as those who "might be ready to vote for candidates who respect women, who are angry about the NRA and school shootings, who believe climate change is real and who want a government that works for the middle class at least as hard as it does for the privileged."
Hillary Clinton couldn't have said it better herself. And therein lies the Democrats' problem. They still don't have a message about the economy or jobs.
The 2018 midterms are the Democrats' to lose. But they need something that appeals to voters besides the Trump-supplied outrage du jour.
If they promise to undo the opportunity and security that comes from a good Republican-produced economy, well, Democrats could squander the opportunity they've been given.