In a memo to Republican House members, Walden outlines the committee's recruitment strategy and a Republican poll conducted in five House battleground districts that indicates the climate is favorable for Republicans.

And because of what he characterizes as a "series of recruitment blows" in key districts, Walden writes that the NRCC is already "aggressively expanding the playing field."

“The question facing Democrats is how, if they are struggling on their home court, will they ever win the Republican-leaning districts they need to regain the majority?” Walden writes.

Democrats are vigorously pursuing majority control of the House, but face a difficult fight as they'll need to net 17 seats to achieve that goal.

And Walden notes a number of Democratic candidates that dropped out of their races soon after announcing bids, including businessman Jim Graves, who exited the race for Rep. Michele BachmannMichele Marie BachmannBachmann won't run for Franken's Senate seat because she did not hear a 'call from God' Billboard from ‘God’ tells Michele Bachmann not to run for Senate Pawlenty opts out of Senate run in Minnesota MORE's (R) seat after she announced her intention to retire, and former state Sen. Staci Appel in Iowa’s 3rd district.

And Walden cites a poll commissioned by the NRCC and conducted by Republican firm Harper polling that shows Republicans leading Democratic incumbents in California's 36th district, Illinois' 10th district and Illinois' 12th district, and Republican Mia Love trailing Rep. Jim MathesonJames (Jim) David MathesonUtah redistricting reform measure likely to qualify for ballot Trump's budget targets affordable, reliable power Work begins on T infrastructure plan MORE (D-Utah) by only 3 percentage points.

The polling also showed Obama's job approval is down in California's 36th district, which he carried in 2012, and that only 38 percent approve of the job Rep. Joe GarciaJose (Joe) Antonio GarciaCurbelo Dem rival lashes out over immigration failure Hispanic Caucus to invite Republicans to join Vulnerable House incumbents build up war chests MORE (D-Fla.) is doing.

And because of President Obama's middling job approval rating — according to the most recent Real Clear Politics polling average, he's slightly underwater with voters — Walden indicates in the memo Republicans will seek to nationalize House races in 2014.

"Democrats are now forced to run with a president who is underwater in polling nationally. If this is a problem in Dem-leaning and swing districts, just imagine the trouble it spells for Democrats in more right-of-center districts — exactly the kind of the districts Democrats need to capture to win the majority," he writes.

But Democratic Congressional Campaign Committee spokeswoman Emily Bittner noted that Democrats performed better than expected last cycle, picking up eight seats, even after Republicans had set out to expand their majority.

House Republicans have confused being on offense with being offensive and polling shows they’ve offended just about everyone. Republicans pledged to be on offense in 2012 and then lost more seats than anyone expected and it looks like they’re headed down the same track," she said.