(Melina Mara/The Washington Post)

Republicans scrambling to salvage control of Congress amid Donald Trump’s downward tailspin have hit on a new message: A GOP-controlled House and Senate are necessary to act as a check on President Hillary Clinton. The message basically argues for divided government as a way to prevent her from going too far, in effect admitting that the presidential race is a goner.

But Democrats insist that this message will be a non-starter, and they shared new internal polling with this blog that they argue backs up their claim. Dems say they can rebut the Republicans’ line of attack by pointing out that they are openly, explicitly promising more obstruction in Washington, something swing voters and independents despise.

The New York Times reports today that the Congressional Leadership Fund, a Super PAC trying to maintain GOP control of the House, will begin airing ads in multiple districts attacking the Dem candidates as “rubber stamps” for incoming President Clinton, as a way to argue that voters should back GOP incumbents. The group’s president says: “In many districts, it is a very, very potent weapon to use against a Democratic candidate for Congress.” Two other GOP-aligned groups are pushing similar messages in multiple Senate races.

But House Democratic strategists tell me they’ve tested their own responses to these messages in over two dozen competitive House districts, and they are not persuaded that Republicans will win this argument.

The Dem firms Garin Hart Yang and Global Strategy Group conducted a poll in mid-September in 30 contested House districts, and here is the key finding:

If it looks like Hillary Clinton is going to win, would you prefer to elect a Democrat to Congress who will work with Hillary Clinton to help her get things done, or a Republican for Congress who would oppose Hillary Clinton’s programs and try to block her from getting anything done?

Prefer to elect the Democrat: 50

Prefer to elect the Republican: 40

The poll, which was conducted for the Democratic Congressional Campaign Committee, surveyed over 1,000 likely voters in the 30 contested districts. It also found that 66 percent of respondents expect Republicans to try to block Clinton even if it means more gridlock and inaction in Washington, while only 23 percent think they will work constructively with Clinton, meaning they’re prepared to believe GOP control means more obstruction.

Now, you should always treat internal polling with skepticism. But this provides hints as to how Democrats view the strategic challenge this new Republican argument presents.

The key nuance here is that Democrats believe the way to win this argument is to reframe it as one about the GOP. Republicans want this argument to be about whether Congress will stand up to overreaching President Hillary, while Democrats want it to be about whether Washington is going to function again or whether we’re going to see more of the same gridlock and dysfunction that GOP control of the House meant during the Obama years.

Kelly Ward, the executive director for the DCCC, tells me that Dems aren’t sure how serious GOP groups — and individual GOP incumbents — are about running with this argument. There are a few examples of GOP ads pushing this line  — see this one in New York’s 22nd District, for instance —  but Democrats are holding off to see how widespread it is before determining how aggressively they’ll respond.

“If and when House Republicans pivot to this ‘check and balance’ argument, the DCCC will answer with paid advertising that calls this for what it is: a promise of more obstruction and gridlock in Washington,” Ward tells me.

But Dave Wasserman, who tracks House races for the non-partisan Cook Political Report, suggests one reason the GOP strategy might work. He notes that the new Republican argument is probably pitched directly at suburban and college-educated white voters who already lean Republican, and may be alienated by Trump, but don’t like Clinton, either. Many of the competitive House races are in suburban districts with a lot of these voters, and they need a reason to vote.

“It’s an argument that resonates with Republicans who don’t like either candidate, and could help the GOP hold onto the House,” Wasserman says.

Of course, Democrats already face an uphill battle to take back the House. They need to net 30 districts, and the Cook Political Report only designates 29 GOP-held seats as “Toss Ups” or “Lean Republican,” meaning there may not be enough genuinely competitive GOP seats, though Democratic strategists believe more are in play.

If and when this battle intensifies, there are two additional angles worth keeping an eye on. The first is that Democrats think this new GOP strategy, with its implicit admission that Clinton is going to win, could drag down GOP turnout. “It risks depressing their support from the Republican base even further, who still very much want Trump to be president,” Ward says.

The other angle worth considering: Given that these are swing districts, is it possible that voter skepticism of Clinton might mean they aren’t receptive to the argument that electing Dems is necessary to help her realize her agenda? If so, Democrats would probably try to keep the argument general by warning that a GOP Congress means more Washington gridlock and fighting, which voters always say they dislike in theory.

But the DCCC’s Ward tells me that Clinton is already faring well in many of these districts. “What the Republicans seem to be forgetting is that Hillary Clinton is going to win the vast majority of the districts in the House battlefield, which provides yet another reason that this strategy will backfire,” Ward says. On the other hand, if the real target of the new GOP strategy is dispirited Republican-leaning voters who need a reason to go to the polls, this might not backfire among them in particular.

Ultimately, a lot of this may end up being determined by how big a margin Clinton runs up in victory. Which we already knew was going to be the case, anyway. At any rate, it looks like this is where the argument is headed next.