Susan Davis

USA TODAY

WASHINGTON — Congressional approval ratings hover at historic lows. The Republican Party's brand has tanked. More people than ever think their own congressman should be sent packing. And the most notable act in one of the most unproductive legislative periods on record was shutting down the government for 16 days.

Yet Republicans are forecast to pick up as many as a dozen U.S. House seats this November, strengthening their grip on the House majority. "I'd rather be us than them," crows Rep. Greg Walden, R-Ore., who chairs the House GOP's 2014 campaign operation.

Democrats say they expect to make gains in the House, but Republicans have a host of built-in advantages this year, including:

• Recently redrawn districts have resulted in fewer competitive seats.

• Historical midterm-election-year trends indicate a limited Democratic turnout.

• President Obama's waning popularity is part of a political climate suggesting that Democrats cannot expect a "wave" election to turn the tide in their favor.

Democrats and Republicans are locked in a competitive struggle over who will control the U.S. Senate next year. But barring a seismic political event between now and Election Day, the GOP's control of the U.S. House is not in question. Here's why.

If it ain't got that swing

It's hard to win the hand when the deck is stacked.

In 2012, congressional district lines were redrawn, as is constitutionally required every 10 years, based on population shifts. Republicans had the upper hand in many states after the GOP won control of governorships and state legislatures following the 2010 Tea Party wave. The end result has been a precipitous drop in the number of competitive seats and a rise in the number of seats considered so safely Republican or Democratic that they are unlikely to ever switch party control.

Today, roughly 50 districts in the 435-member House make up the entirety of the 2014 battleground.

The non-partisan Cook Political Report ranks just 16 of those districts, 13 held by Democrats and three by Republicans, as competitive enough that neither party has a clear advantage with fewer than 100 days to go before Election Day.

The current House makeup includes 234 Republicans and 199 Democrats, and there are two vacant seats that are safely Democratic. That means Democrats need a net gain of 17 seats for a takeover. They'd have to pick up 17 Republican seats and lose none of their own, or make even greater gains in GOP territory to make up for any losses.

Rep. Steve Israel, D-N.Y., who runs the House Democrats' campaign operation, maintains that the election climate is still unfolding. He believes Democrats could easily benefit from mounting voter frustration at the House GOP's ongoing struggles with governing. "You're going into a midterm election with voter revulsion aimed at Republicans," he says.

At a recent roundtable with reporters, Israel would not concede that Republicans will maintain control, but he stopped short of predicting a Democratic majority. "My job is not to get hung up in punditry but to obsess on what's in my control," he says.

However, he agreed that Democrats need to do a better job in the next round of redistricting to level the playing field.

"We have to be smart and better going in to the 2020 redistricting, I will say that," he says.

The downside for Democrats?

They won't have a chance to run in new, redesigned districts until the 2022 elections.

The midterm voter

To Democrats' advantage, their long-term future includes a broader, more diverse and expanding base of young people, women and minorities.

To Democrats' detriment, their voters are less likely to show up in midterm elections than Republicans' older and whiter base.

To Democrats' 2014 peril, this year is on track to maintain that trend.

"I am absolutely sure (turnout) will be lower than 2010 or 2006," says Curtis Gans, an expert on voter turnout. While Gans is more bullish on Democrats' prospects than most election handicappers, he also maintains that Democrats can't take back the House this year.

"I don't believe Democrats can get control of the House. I do believe they might pick up some seats," he says. In a recent detailed analysis, Gans found that primary turnout has been low throughout the first 25 states to hold those contests. Only 18 million of the 123 million voters eligible to cast primary ballots did so thus far this year.

Low primary turnout isn't necessarily indicative of low turnout come November. To get more of their people to the polls, Democrats are plowing resources into voter registration drives and get-out-the-vote programs.

The House Democratic campaign operation doubled its grass-roots mobilization effort for the 2014 cycle and recently launched "1 Million Votes for 2014" to register new voters in time for the election. Israel says the party has already achieved 120,000 commitments to vote.

Most voters don't start tuning in to election season until after Labor Day, so Democrats have time to maximize their turnout. "The Democrats could make a very good case that they've done some things and Republicans have done nothing but obstruct," Gans says. "When you have a Congress with a 7% approval rating, at some point, that's got to take a toll."

No wave in sight

In order to take back the House, Democrats would need a "wave" election in which one party enjoys dramatic political gains. But there is no wave on the horizon, largely because of the president's unpopularity. There have been only four times in the past two decades in which the House saw a net seat change in the double digits. In those four election years — 1994, 2006, 2008 and 2010 — the wave was fueled by backlash against the incumbent president's party.

Republicans won control of the U.S. House under President Clinton in 1994; Democrats won control back and increased their majority under President Bush in 2006 and 2008. Republicans returned to the majority in 2010 with the Tea Party-inspired wave under Obama. The prospect of 2014 becoming a wave election year benefiting congressional Democrats is more than just unlikely. It would be unprecedented in modern politics.

Obama and the six-year itch

Democrats are also facing a trend commonly known as the "six-year itch," in which the president's party historically loses seats in Congress. Not all presidents have fallen victim to it — Clinton enjoyed congressional gains in 1998 — but Obama is not expected to experience a repeat, and Clinton's gains were not enough to switch party control.

While Obama has worked to build the campaign war chests of the House and Senate Democratic campaign operations this year, he's been largely absent on the campaign trail, where Democrats in tight races are seeking to portray themselves as independent of the president and his agenda. "They have to run from their leaders; they cannot embrace them," Walden said. "The only thing they can embrace is the fundraising."

The best chance that House Democrats have for making a play for control may be in 2016, where the lift of a popular Democratic presidential nominee who can appeal to voters in conservative-leaning states could boost candidates down ballot.

Democrats are laying the groundwork for that election by building better voter databases, registering voters and solidifying their support among women and minority voters, especially Hispanics. What is clear is that the 2014 election is unlikely to change Obama's loyal GOP opposition in Congress. In fact, if House Republicans' achieve Walden's stated goal of an 11-seat gain, or a 245-seat majority, next January would usher in the biggest GOP House majority since the Hoover administration.