History tells us that the party that holds the White House faces an uphill battle in the midterm elections.

Broken or delayed promises, bitterness over a presidential candidate’s loss and lack of confident in anything coming out of Washington seem to always add up to heartbreak for the party in power.

If this was a traditional White House, the likelihood of a “blue wave” come November -- a surge of Democratic candidates gobbling up Republican seats in Congress – would seem a certainty.

But you could rightly ask with this administration, “What does history have to do with anything?”

Yet polls are pointing toward a shift in the balance of power in Washington. Just how big a shift is yet to be seen.

Various pundits have Democrats taking control of the House of Representatives and making a good run at grabbing the reins in the U.S. Senate.

Polls also claimed that Donald Trump would be defeated by Hillary Clinton for the presidency in 2016.

A recent Washington Post-ABC News poll showed that while Democrats hold an advantage ahead of the midterm elections, that advantage has narrowed since January. Narrowed by half.

So where do we stand 194 days out? Here’s a look at the races in the U.S. House this year.

First some numbers: 

For a party to gain control of the House, they must hold 218 seats. In the current Congress, Republicans have 236 seats and the Democrats have 193 seats.

Where do the Republicans stand?

You may be wondering amid the predictions of a blue wave if anything can help Republicans in the fall? The answer is yes, a few things could. The most important being a solid economy.

Remember the tax cuts Congress passed and the bonuses that some companies handed out this year? Well, the GOP wants you to hold fast that memory, at least until November.

Gallup's Economic Confidence Index showed that residents in only seven states rated the economy as more negative than positive. The poll was taken last year so participants were commenting on the 2017 economy -- prior to the tax cuts that went into effect on Feb. 1.

In 2016, the picture was much darker. Forty-five states had net-negative evaluations of the economy.  

An uptick in Trump's poll number is something else that would help Republican candidates' chances. Previous presidents with poll numbers as low or lower than Trump's saw disaster in the midterm elections.

Traditionally, a low congressional approval rating points to a significant change in the numbers in Congress. The president's party, on average, loses 29 seats when the approval rate for Congress is below 40 percent. The approval rate for Congress today stands at 18 percent.

In November 2014, when Barack Obama was president and Republicans took control of both the House and the Senate, the approval rate was 15 percent.

Where do the Democrats stand?

What is going right for the Democrats this year? A lot. Add lower approval ratings for Trump and for Congress to 40 retirements by incumbent GOP senators and representatives and a path to a “blue wave” looks pretty good.

Special elections have seen no partisan switch during the past year with the exception of the Senate race in Alabama won by Democrat Doug Jones and a House race in Pennsylvania won by Democrat Conor Lamb. There are five upcoming special elections this year.

But what Democrats are hanging their hat on is the overperformance of their candidates. Even in a loss, Democrats are seeing candidates who would have had little chance to make a showing in long-held GOP strongholds come in a very close second.

So, what good is second place? The benefit comes from the number of registered Democrats who are turning out to vote. Democratic Party leaders are bolstered by big turnouts for primaries and are banking on dissatisfaction with Trump to spur even higher numbers for the general election.

According to a Washington Post/ABC News poll, more Democrats are pledging to turn out for the midterm elections.

Here’s a look at how the election could shape up, which races are the most likely to be competitive and why they would be so.

What can make races competitive? 

With not all races set, it can be difficult to pick the most competitive contests, but a big indicator of how a district will vote is the result of the presidential race in that district. In the 2016 election, 35 districts split their ticket – voting for a candidate of one party for president and a candidate of the opposite party for representative.

Twenty-three districts across the country went for Clinton for president but voted for a Republican for representative. Twelve districts went for Trump for president but sent a Democrat to the House to represent the district.

Here is a look at those districts.

Which races are likely to be competitive?

In the districts in which Hillary Clinton won in the 2016 presidential race, 23 are held by Republican incumbents – possibly making them vulnerable in the midterm elections. Those districts and representatives are:

  • AZ-02 – incumbent Martha McSally (she is running for the Senate and will not seek re-election)
  • CA-10 – incumbent is Jeff Denham
  • CA-21 – incumbent is David Valadao
  • CA-25 – incumbent is Stephen Knight
  • CA-39 – incumbent Ed Royce is not seeking re-election
  • CA-45 – incumbent is Mimi Walters
  • CA-48 – incumbent is Dana Rohrabacher
  • CA-49 – incumbent Darrell Issa is not seeking re-election
  • CO-06 -- incumbent is Mike Coffman
  • FL-26 – incumbent is Carlos Curbelo
  • FL-27 – incumbent Ileana Ros-Lehtinen is not seeking re-election
  • IL-06 – incumbent is Peter Roskam
  • KS-03 – incumbent is Kevin Yoder
  • MN-03 – incumbent is Erik Paulsen
  • NJ-07 – incumbent is Leonard Lance
  • NY-24 – incumbent is John Katko
  • PA-06 – incumbent Ryan Costello, is not seeking re-election
  • PA-07 – The 7th district was redrawn and there is no incumbent. The new 7th district was created from three districts.
  • TX-07 – incumbent is John Culberson
  • TX-23 – incumbent is Will Hurd
  • TX-32 – incumbent is Pete Sessions
  • VA-10 – incumbent is Barbara Comstock
  • WA-08 – incumbent Dave Reichert is not seeking re-election

Of the districts won by Trump in the 2016 election, 12 are held by incumbent Democratic representatives. Those districts are:

  • AZ-01 – incumbent is Tom O'Halleran
  • IA-02 – incumbent is Dave Loebsack
  • IL-17 – incumbent is Cheri Bustos
  • MN-01 – incumbent Tim Walz is running for governor and will not seek re-election
  • MN-07 – incumbent is Collin Peterson
  • MN-08 – incumbent Rick Nolan is not seeking re-electon
  • NH-01 – incumbent Carol Shea-Porter is not seeking re-electon
  • NJ-05 – incumbent is Josh Gottheimer
  • NV-03 – incumbent Jacky Rosen is running for U.S. Senate rather than for the House seat
  • NY-18 – incumbent is Sean Maloney
  • PA-17 – The new 17th District was redrawn by court order. It is made up of parts of the old 3rd, 12th, 14th, and 18th districts.
  • WI-03 – incumbent is Ron Kind

Other races that could help to flip – or hold on to – the House

There are other races that some believe could change the balance of power in the U.S. House. These 14 races have also been pegged by various media outlets as “competitive.”

  • CA-22 – Devin Nunes  
  • CO-06 – Mike Coffman  
  • IW-01 – Rod Blum  
  • MI-11 – David Trott  
  • MN-02 – Jason Lewis  
  • NB-02 – Don Bacon  
  • NV-04 – Ruben Kihuen  
  • NJ-02 – Frank LoBiondo  
  • NJ-11 – Rodney Frelinghuysen  
  • NY-19 – John Faso  
  • NY-22 – Claudia Tenney  
  • PA-15 – Charlie Dent  
  • UT-04 – Mia Love

Sources: Ballotpedia; The Associated Press; Politico; The Washington Post; The Cook Political Report