House Democrats believe the shutdown will help them put the lower chamber in play this cycle.

Democratic candidates running against vulnerable Republicans have wasted no time in hammering the incumbents as key actors in what they're characterizing as a Tea Party-led shutdown that's hurting Americans.

Many of those Republicans, in a signal they're concerned about the possible political ramifications, are calling for an end to the stalemate — like Reps. Scott RigellEdward (Scott) Scott RigellGOP rushes to embrace Trump GOP lawmaker appears in Gary Johnson ad Some in GOP say Trump has gone too far MORE (R-Va.), Pat Meehan (R-Pa.) and Jon Runyan (R-N.J.), all of whom are facing reelection in difficult districts and all of whom called this week for the passage of a clean CR to end the shutdown.

Multiple polls, too, have shown Americans are placing the blame for the shutdown on Republicans.

Democrats need to pick up 17 seats to win back the House, a tall order under any circumstances, and even taller in an off-year when the party holding the White House typically loses seats.

But Democratic Congressional Campaign Committee Chairman Steve Israel (D-N.Y.) told The Hill on Friday that the shutdown “may widen our path to 17 seats,” and potentially allow them to drive deeper into the map.

“It’s lethal,” Israel said of the shutdown’s effect on the Republican brand.

“Every poll that I see in our 53 competitive Republican districts say that people want cooperation. But not one single House Republican who claims that they want a compromise in a press release back home has been willing to vote for one on the floor of the House,” he added.

“So we're going to hold Republicans accountable for acting like independent pitbulls in their district when they’re nothing but loyalist lapdogs in their caucus.”

Even some Republicans are sounding the alarm.

Rep. Peter King (R-N.Y.), who has been pushing for passage of a clean CR, affirmed, when asked, that the shutdown could put control of the House into play.

“Yes, by hurting us with independent voters in swing districts,” he said.

King said his vulnerable colleagues had privately expressed “real concerns,” and that one lawmaker running for reelection in a swing district told him he was getting calls “400-to-1 negative” about the shutdown.

“The longer it goes on the more we get identified as the problem. It’s one thing if it’s unpopular for philosophical reasons. People can disagree on an issue. But on this, it shows that we don’t know how to govern, that we're dysfunctional,” he said.

“That’s different even from agreeing to disagree on a solution.”

Like King, Democrats believe the shutdown feeds into a larger argument they’re making about the GOP, one that they hope resonates in 2014: It’s a party of obstruction and dysfunction, hell-bent on opposing anything the president wants to do and shackled by its extreme Tea Party fringe.

“The problem for House Republicans is that voters already view them as intransigent and the roadblock to getting anything done in Washington. This reinforces that,” said Andy Stone, Communications Director at House Majority PAC, a major super PAC working to elect Democrats to the House.

HMP this week launched a six-figure advertising campaign slamming its top nine targets for the shutdown with search engine and television ads. The DCCC hit more than 60 House Republicans with robocalls on the issue.

House Democrats think it will play particularly well in those suburban swing districts where they’re pushing candidates they see as “problem-solvers,” who are running post-partisan, anybody-but-Washington campaigns against GOP incumbents.

One such Democratic candidate, Ann Callis, challenging Rep. Rodney Davis (R-Ill.), held a press conference on Friday back in Illinois’ 13th district with furloughed federal workers to talk about the impact of the shutdown.

In a release issued as the shutdown began, Callis said the shutdown was an example of the fact that ‘the dysfunction in Washington makes it even more important that we elect people who are more focused on common-sense solutions.”

Davis said he wasn’t surprised he’s being attacked from the left, but that he doesn’t believe it will hurt him because Americans will realize Democrats are putting “politics over people.”

“This is a typical blame game. And I’d like to see the DCCC tell the president of the United States and the Democrats in the Senate to come to the table and help us come up with a solution,” he said. “The American people are demanding it. It’s not about throwing temper tantrums, it’s about actually governing.”

Like Davis, many Republicans believe that if Democrats push too hard in politicizing the shutdown, they could suffer a backlash.

And their current strategy to tackle the shutdown, by passing piecemeal appropriations bills, could enhance the backlash.

The House this week failed to pass bills that would fund the D.C. government, veterans benefits and national parks.

The bills were brought to the floor by the GOP in a way that required Democratic votes to pass, putting Democrats on-record as opposing funding for a wide range of noncontroversial government functions.

Those are the kinds of votes that could make for particularly damning attack ads later on in the cycle. That explains in part why anywhere from 20-30 vulnerable Democrats — like Reps. Ron BarberRonald (Ron) Sylvester BarberPrinciples and actions mean more than Jeff Flake’s words Giffords to lawmakers avoiding town halls: 'Have some courage' Ten House seats Dems hope Trump will tilt MORE (Ariz.) and Mike McIntyre (N.C.), both facing difficult races of their own — defected from their party and voted in favor of the piecemeal bills, even as Democratic leadership pledged to oppose the approach.

National Republican Congressional Committee Communications Director Andrea Bozek said in an email that Democrats were politicizing the shutdown rather than trying to find a solution.

“It’s disappointing that Chairman Israel is trying to score political points while vital cancer research and veterans disability payments are being suspended,” she said.

Still, some Republicans warn the ramifications of the shutdown could ripple much farther and deeper than through just House elections — and, as King said, permanently hurt the GOP brand.

“The governors are really getting concerned about this. And the senators, because they have to run statewide,” he said. “If this continues, you’re going to see the Republican brand being hurt.”