The National Republican Congressional Committee is facing the daunting task of defending almost four dozen seats where the GOP incumbent has retired, lost in the primary, or is running for another office.  This is more than twice the average number of open seats than in past midterm elections.

In addition, there are about a dozen Republican incumbents running in districts won by Hillary Clinton and several more that are in danger due to redistricting.  When political analysts talk about a "favorable Democratic map," this is what they mean.

The House Republican campaign organization has looked at that map and, with 40 days to go before the polls open, is beginning to make some hard choices about where its limited resources should go. 

The Hill:

For the GOP, it's likely a sign of things to come as the party seeks to target its money toward the races most likely to save its majority.  Democrats need 23 seats to take back control of the House, and the GOP is defending dozens of seats that are seen as vulnerable. 

"It's a giant chessboard," said one longtime GOP operative.  "There's obviously limited resources, and you need to make tough decisions.  This is sort of an art form as opposed to a science."

The National Republican Congressional Committee (NRCC) must decide if it should put energy into competitive and Democratic-leaning districts that Hillary Clinton carried in 2016 – or if the party is better served protecting GOP strongholds that could be in play if a "blue wave" materializes.

It's not as hopeless as it seems, nor is it as favorable as Democrats would have us believe.  The majority of those open seats are in strong GOP districts where the Democrat isn't competitive.  The GOP could run Mickey Mouse and probably keep the seat.

In addition, Gallup's most recent survey of party favorability gives some hope to Republicans:

Heading into the November midterms, the Republican Party is the most popular it has been in seven years, according to a Gallup poll released Monday.

The poll found 45 percent of Americans view Republicans favorably – a 9-point increase from one year ago, when the GOP had a 36 percent favorable rating.

There has been much talk about Democratic voters being more "enthusiastic" than Republicans.  A Wall Street Journal poll found GOP enthusiasm surging:

The Journal said, "The poll, while outlining challenges for the GOP, included some good news for Republicans.  The party is closing an enthusiasm gap, with 61 percent of Republican voters now expressing high interest in the election, nearly matching the 65 percent of Democrats.  In polls taken over the first eight months of the year, Democrats had held an aggregate 12-point advantage in the share of supporters showing high interest in the election."

And NBC said, "Still, the same poll shows that Republican enthusiasm about the upcoming election has increased, drawing nearly even with Democrats." 

Historically, the party that holds the presidency loses about 30 seats after the first midterm election.  Trump's favorability is under water but better than it was a few months ago, and as the Democrats seek to nationalize the election, other historical factors come into play.

The bottom line is that for Democrats to take the House, key voting groups must turn out to vote in far greater numbers during a midterm election than they have in the past.  Minorities, the young, single women, and those with a college education have historically failed to show up at the polls in sufficient numbers during the midterm elections.  No matter how "energized" they are because of anti-Trump hysteria, they still have to get up off the couch, drive to the precinct, and vote.  This, they have failed to do in recent midterm elections.

If they do show up, it is probably curtains for the GOP – certainly in the House, and perhaps even the Senate.  But while the numbers presently look grim for Republicans, it's not the sure thing many Democrats are predicting.  The Kavanaugh fight could easily backfire on Democrats and energize Republicans while disgusting many ordinary voters.  Then there is the real "X" factor in Trump.  Trump's popularity with Republicans could tip the balance in several close races.  In the coming weeks, the president will be out on the stump, trying to get Republicans to the polls on election day.

History also tells us we shouldn't bet against him.