Steven Gold, a sociologist at Michigan State University, emailed me:

Many Democrats fear that extensive investments and political posturing made on behalf of immigrants will be regarded as of little value to a large swath of independent voters whose support Democrats need to increase their representation in Congress.

In a reference to the demonstrated electoral liabilities of so-called “identity politics,” Gold argued that concerned Democrats worry that

by emphasizing particularistic rather than practical issues with a broad impact, they will once again lose the politically advantageous position that appears to be taking shape for them in 2018 and 2020.

More bluntly, Nolan McCarty, a political scientist at Princeton, declared in an email responding to my inquiry:

The Democrats don’t have a lot of good options other than to support it enough that it can pass with unified Republican support.

McCarty explained further:

Blocking it would allow the Trump Administration to suggest that the Democrats were willing to trade Dreamers for “lottery” and “chain” migration, as well as position them as soft on border security.

An advantage in accepting the Trump proposal, McCarty continued,

is that border security appropriations and visa programs can be fixed if the Democrats regain control. The effects of Dreamer deportations and/or sending them back into the shadows is far less reversible.

Trump and Stephen Miller, a senior adviser to the president, have clearly made this calculation and decided that they win either way. Take, for example, the following tweet from the president’s account on Jan. 27:

I have offered DACA a wonderful deal, including a doubling in the number of recipients & a twelve year pathway to citizenship, for two reasons: (1) Because the Republicans want to fix a long time terrible problem. (2) To show that Democrats do not want to solve DACA, only use it!

Robert L. Borosage, president of the left-liberal Institute for America’s Future, argued that Democrats should make every effort to get the immigration issue off center stage. “In my view,” Borosage said in an email, “Trump wins as long as we’re arguing about this. So it would be good to get this done soon.”

Borosage went on:

What should Democrats do? I’d take the deal, after pushing for concessions on family unification and lottery system, and pushing against full commitment of $25 billion as an outrage.

Bruce Cain, a political scientist at Stanford, makes the case that political logic favors Democratic cooperation with Trump on immigration:

If the Democrats compromise on a few of the non-DACA items and the (Congressional) Republican position is no DACA relief, then the Republican position becomes untenable and looks as though are caving to their extreme nativist faction. And if the Democrats make their position a clean bill on DACA and no compromise on the other items, it hands the Republicans a perfect wedge item going into the 2018 election, possibly keeping them in control of both houses.

In fact, I found an unexpectedly high percentage of the experts I contacted — most of whom are sympathetic to the plight of immigrants — in general agreement that Democrats would be wise to come to some kind of an agreement with Trump.

Daniel Hopkins, a political scientist at the University of Pennsylvania, noted, for example, that the public supports both “a pathway to citizenship for Dreamers” and “enhanced border security.” But, he warned,

in today’s political climate, it’s very hard to imagine a deal that will placate both sides for long, as both parties seem to define winning in zero-sum terms.

So far at least, arguments in favor of cutting a deal are not selling with the Democratic leadership — although the leaders’ position may be more of a bargaining tactic than a principled stance.

Chuck Schumer, the Senate Democratic leader, tweeted on Jan. 26 that “this plan flies in the face of what most Americans believe,” adding

While @realDonaldTrump finally acknowledged that the Dreamers should be allowed to stay here and become citizens, he uses them as a tool to tear apart our legal immigration system and adopt the wish list that anti-immigration hard-liners have advocated for years.

Nancy Pelosi, the Democratic House leader, was more outspoken. In a Jan. 26 statement that received wide press coverage, she described Trump’s proposal as “part of the Trump Administration’s unmistakable campaign to make America white again.”

After Trump reiterated his immigration proposals in his State of the Union address Tuesday night, Pelosi stood firm in her opposition:

The president represents himself as generous towards Dreamers, but he is holding them hostage with the most extreme anti-immigrant agenda in generations. We heard more insulting words of ignorance and prejudice towards patriotic immigrant families last night.

In a detailed critique of the Trump proposal, William Frey, a demographic specialist at Brookings, argued that

the so-called compromise between DACA and border security is extremely disproportional — weighted heavily toward the latter which is characterized by simple bumper sticker messages about family migration, border security and the visa lottery that is aimed at appealing to the extreme anti-immigrant wings of Trump’s Republican base.

Frey wrote in his email that he could

not imagine Democratic senators or congressmen agreeing to anything close to this plan — in light of their base which not only includes Hispanics, Asian-Americans and other minorities — but also rising support in recent state and local elections they have received from suburban college graduate women and millennials.

Nonetheless, in a Washington Post op-ed published in 2015, Frey pointed out that

Democrats cannot make the politics of fear go away simply by courting the young-adult and minority voting blocs. While it is true that the supersize turnout and support of those groups helped elect President Obama twice, the white portion of the electorate, which votes strongly Republican, underperformed in support of John McCain in 2008, and white turnout was down in 2012.

There is, Frey continued, “a sharp lag in diversity between the overall population and the portion that turns out on Election Day.” It is “the older electorate — those most greatly fearing change,” he wrote,

that will be gaining as baby boomers continue to age. By my calculation, the number of (mostly white) eligible voters over age 45 will be 26 percent larger in 2024 than those under age 45. This disparity will be further widened by the higher turnout of older white voters, who may not determine future elections but will continue to have a strong voice.

When I asked him if there was a disparity between his recent comment to me and the Post op-ed, Frey wrote back:

I stand by the fact that the politics of fear (to older non-college whites) can work to some extent. But I also think white women, especially college graduate white women, can help to mute the impact on the immigration issue because of their disdain for Trump. If Dems are looking at 2018, it’s not just the immigration issue that is important to those women but Trump’s stance on women’s issues in general — critical of planned parenthood, abortion, his support of Roy Moore in Alabama, his disdain for political correctness and his overall boorishness may counter whatever gains he may get, on immigration, from older white non-college men and women (and even the latter support may be more tenuous). Another group is millennials, now strongly anti-Trump, who could be motivated to turn out in greater numbers. In short, the base that will respond to Trump playing the “immigration card” may be dwindling in light of his other positions and demeanor since in office — including his handling of the Russian investigation. I think the Democrats are counting on that.

It may seem surprising now, but the Pew Research Center found that from 1994 to 2006 there was very little difference between the views of Republican and Democratic voters on immigration. Since that time they have diverged sharply.

In response to the question, “Which comes closer to your view, ‘immigrants today strengthen the country because of their hard work and talents,’ or ‘immigrants today burden the country by taking jobs, housing and health care’?” there was almost no difference in the responses of Democrats and Republicans in 2006.