(Bloomberg) -- If November delivers the wave election that Democrats hope will give them control of the U.S. House, it’s almost certain to wash through Pennsylvania.
Results from Tuesday’s primary in the battleground state will offer fresh insight into whether Democrats can seize an opportunity -- or miss a chance -- to end one-party control of Washington under President Donald Trump.
Trump narrowly won Pennsylvania in 2016, but the state has two of the main ingredients that could benefit Democrats in this year’s closest House races: suburban swing districts and an abundance of female candidates in a year when women are showing unprecedented levels of political engagement. Nine of the state’s 18 House races are rated as competitive.
Democrats need a net gain of 23 seats to win control of the House from Republicans, and the party has some reason to be optimistic about achieving that and more in the general election. The party scored notable wins in 2017 and 2018 state and special elections, fundraising is robust, swarms of candidates have filed to run under its banner and Trump’s job approval remains stuck at around 40 percent.
But Election Day is still six months away. Trump’s approval rating has been ticking up, though slowly, and the economy continues to add jobs. An unforeseen domestic or international crisis could suddenly shift the fortunes of either party.
It would be “a little foolhardy” to forecast a wave election at this stage of the campaign, Iowa-based pollster J. Ann Selzer said, though she sees Democratic advantages.
“The cards appear to be sort of be stacked that way, for now,” Selzer said. “But those congressional races are so much a product of the individual people.”
Republicans are trying to buck a historical trend in which the party that holds the White House almost always loses congressional seats in midterm elections. This year there is an unusually large number of House seats where there is no incumbent -- seven in Pennsylvania and more than 50 nationally -– adding to chances for an upheaval.
Both parties are closely watching the so-called generic ballot question in polls that ask voters which party’s candidate they would vote for in their House district, without candidate names being mentioned.
At the start of the year, Democrats held an advantage of as much as 12 percentage points. But in recent weeks, as Trump’s approval has ticked up a few points, their lead has narrowed. A Pew Research Center poll at the end of April had it at five points and survey released last week by CNN showed the Democratic edge down to three percentage points.
A review of economic and political fundamentals ahead of midterm elections in 1994, 2006 and 2010 -- the three most recent wave elections -- shows landslides are hard to predict and no two look alike.
The 2006 election has some parallels to conditions in 2018. Democrats held a 10-point advantage on the generic ballot in a Pew Research Center survey at this point in 2006, in the middle of President George W. Bush’s second term. Both early 2006 and early 2018 share the backdrop of a relatively strong economy, with an unemployment rate below 5 percent and the economy growing around 3 percent from a year earlier.
In April 2006, Bush’s approval rating was 33 percent in a Pew survey, dragged down primarily by public dissatisfaction with the war in Iraq. That’s lower than the 39 percent recorded by Trump in an April Pew poll.
In that election 12 years ago, Democrats went on to pick up 31 House seats and six Senate seats.
John Lapp, a strategist who served as executive director of the Democratic Congressional Campaign Committee at the time, said he thinks his party is positioned more favorably now than then.
“In 2006, everything happened much, much later and the energy happened later,” he said. “It was a much tighter map then than today.”
Analysts who track House races aren’t ruling out the possibility of a wave. They’re also not predicting one.
"The range of possible outcomes is still pretty wide," said Kyle Kondik, managing editor of Sabato’s Crystal Ball, a campaign-tracking project of the Center for Politics at the University of Virginia in Charlottesville.
"I could see the Democrats sputtering out and only picking up 10 to 15,” he said. “At the same time, I could also see there being a giant wave where Democrats pick more like 45 to 50."
Democrats will have a much tougher time reversing the 51-49 Republican majority in the Senate. They are defending 26 Senate seats in November, compared with just nine for the Republicans, and 10 of those Democratic incumbents are running in states Trump won in 2016, including Pennsylvania.
In the House, though, Minority Leader Nancy Pelosi of California is "bullish" on her party’s chances of winning control.
"I feel very confident," she said at a May 9 Politico Playbook breakfast in Washington. "I wish the election were today, but it isn’t today, so we have to keep putting one good day in front of another."
Republicans say Pelosi and other Democrats are getting ahead of themselves.
"Their overconfidence right now is emblematic of a larger problem in the Democratic Party: that they don’t seem to understand that they actually need a message that resonates with independent-minded voters who are going to decide these elections," said Jesse Hunt, press secretary for the National Republican Campaign Committee. "Simply saying that this is going to happen because we believe that energy is on our side is not enough."
In Pennsylvania, it’s certain there will be significant House turnover because of retirements and a court-ordered redrawing of congressional districts after the state Supreme Court found Republican-drawn boundaries were unconstitutionally gerrymandered to favor the GOP.
The suburbs of Philadelphia and Pittsburgh are critical to Democratic prospects. The nonpartisan Cook Political Report rates two suburban districts west of Philadelphia as likely Democratic wins. One district that includes Allentown is listed as “lean Democratic,” while one west of Pittsburgh and one north of Philadelphia -- both with incumbent Republicans running – are listed as "toss up" races.
Twenty women, all but one of them a Democrat, are running in Pennsylvania’s primary, in some cases against each other, to break into what is now an all-male congressional delegation. Of the 10 Democrats vying for the nomination in the strongly Democratic 5th District near Philadelphia, six are women.
Primaries will also be held Tuesday in Nebraska, Oregon and Idaho.
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