Would Democrats really shut down D.C. over DACA? If so, Republicans have a message for them:

Good luck with that.

At first glance, Democrats would appear to have the upper hand on getting a deal for the 700,000 or so people covered by the "Deferred Action for Childhood Arrivals" -- President Obama's unilateral granting of immunity from immigration enforcement to people who were brought to America as kids when their parents came to America illegally.

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Polls show that most Americans want to find a way for these (now young adults) to stay. President Trump said he wants a deal that lets them stay when he announced he was letting President Obama's possibly illegal executive order expire in order to get Congress to "do its job" and pass a permanent solution.

Then there's looming deadline for a spending deal that also works against the Republican majority who, with the upset election of Doug Jones in Alabama, are down to 51 votes and need 60 to pass any deal.

No wonder the progressive base of the Democratic Party wants a fight to the death to force through a "clean DACA deal." They've told the Democratic leadership: No new immigration restrictions, no increase in enforcement and—absolutely—no money for Trump's border wall. Either pass DACA, or shut the government down.

"We are laser-focused on January 19 as a do-or-die moment," Greisa Martinez of the advocacy organization United We Dream told The Washington Post. The Senate math gives Democrats power, Martinez notes, and progressives expect them "to meet their public and private commitment to us that they'll use every leverage they have."

Progressive organizations like United We Dream, MoveOn.Org and CREDO are pressuring Democrats to reject any compromise on DACA, in the wake of a short-term spending patch Democrats helped pass last month to keep the government open over the holidays. Their response was to label the 18 Senate and 14 House Democrats who voted for that compromise the "Deportation Caucus." They are promising to highlight these votes in the midterm elections later this year, or even support opponents in Democratic primaries.

And these efforts are already beginning to pay off. California Democrat Dianne Feinstein had been a vote for a compromise, but now—facing a serious primary opponent from her left—voted against the spending bill last month and claims to want a "Clean DACA."

So why aren't Republicans acting worried? Why is President Trump still pushing for $18 billion in funding for a border wall and announcing his plans to tour border-wall prototypes near San Diego after the State of the Union?

Because border security is a bad issue for Democrats. Yes, the infamous wall remains unpopular, but well more than 60 percent of Americans continue to say they want increased border security as part of a deal for the Dreamers.

As Sen. Tom Cotton (R-Arkansas) said on ABC this weekend: "I don't expect a government shutdown, I don't want one. But if Democrats want to shut down the government because they can't get amnesty for illegal immigrants, they'll have to explain that to the American people."

Explaining opposition to the wall is easy. But the GOP proposal also calls for an end to "diversity visa lotteries," and chain migration. Republicans also want to take action against so-called "sanctuary cities."

A majority of Americans oppose all of these policies, with the opposition to "sanctuary cities" hitting 80 percent in one poll last year. And Americans consistently support tougher immigration enforcement in general, including more Border Patrol agents and the use of E-Verify to prevent ineligible workers from gaming the system and getting jobs.

Even worse for Democrats, recent high-profile news stories have highlighted the dangers of the very policies their base opposes. Most people are aware of the shooting of Kate Steinle by a repeat offender who was not turned over to federal authorities due to San Francisco's "sanctuary city" policy. But the two recent terrorist attacks in New York—the Manhattan truck attack on Halloween, and a failed suicide bombing attempt at the Port Authority—both involved attackers who took advantage of these liberal immigration loopholes.

There is a deal practically sitting on the table right now: Republicans agree to amnesty for those covered by DACA, President Trump gives up on direct funding of the wall, and Democrats agree to common-sense reforms like E-Verify, ending chain migration and killing the diversity lottery.

Once the GOP makes the first two moves—and I predict they will--do Democrats really shut down the government defending these difficult to defend and broadly unpopular policies?

No wonder Republicans don't seem worried.