Democrats face some tough spending decisions ahead of November as Republicans have expanded their national ad blitz.

The big question facing the Dem Party: Do they protect vulnerable newcomers, or do they build a firewall around veteran incumbents who are GOP targets?

Both parties are preparing to finalize their midterm spending bets over the course of the next two weeks, with the Democratic Congressional Campaign Committee (DCCC) forced to decide which incumbents it will stand by and which may be polling too far behind their GOP challengers to save.

“You’re approaching that decision time probably within the next seven days,” said one Democratic operative familiar with the process.

The pressure on the DCCC has increased thanks to the latest round of ad spending just rolled out by the National Republican Congressional Committee (NRCC). Over the last four days, the committee has released 20 new independent expenditure (IE) ads.

The NRCC is on the air in 30 districts as of Monday morning, targeting mostly vulnerable Democratic incumbents, with the committee pouring more than $350,000 into ad buys against Rep. Mark Schauer (D-Mich.), $158,307 against Rep. Dina Titus (D-Nev.), some $115,827 targeting Rep. Earl Pomeroy (D-N.D.) and just under $150,000 against Rep. Paul Kanjorski (D-Pa.).

Meanwhile, the DCCC has been holding its fire. It has reserved ad time in 57 congressional districts but only run ads in 12, including two Democratic-held open-seat races and one Republican-held seat.

Vulnerable members like Reps. Titus, Tom Perriello (D-Va.) and Ann KirkpatrickAnn KirkpatrickMajor progressive group endorses Martha McSally challenger Women make little gains in new Congress McCain wins sixth Senate term MORE (D-Ariz.) have yet to receive advertising assistance from the DCCC.

And the NRCC has spent some $340,000 on IE ads against those three Democratic incumbents alone.

The DCCC has canceled two weeks of ad time in Las Vegas for Titus, according to a Republican who tracks Democratic ad buys. 

Earlier, the committee scaled back its $1.2 million reservation in the Phoenix media market, which covers Rep. Harry Mitchell (D) and Kirkpatrick’s districts.

“It’s pretty clear they’re cutting their losses in Arizona and Las Vegas is looking too expensive for them,” said one Republican strategist who tracks the buys.

Democratic strategists maintain that any rollbacks in the party’s ad reservations are being made based on the strength of the incumbents’ campaigns.

“Our members are all running strong campaigns focused on their solid records and drawing sharp distinctions between themselves and their flawed Republican opponents on the key issues at stake in this election,” said Ryan Rudominer, a spokesman for the committee. “The DCCC is heavily invested in these campaigns.”

Meanwhile, the DCCC is beefing up its ad buy in Wilkes-Barre, Pa., which could go to help Reps. Chris Carney (D-Pa.) and Kanjorski. It has already reserved more than $750,000 in the media market but has doubled that to $1.5 million, according to a GOP strategist.

The committee also has yet to spend in districts represented by several longtime Democratic incumbents who face real challenges this fall, including Reps. John Spratt (S.C.), Ike Skelton (Mo.), Chet Edwards (Texas) and Pomeroy.

It’s canceled two ad buys in North Dakota for Pomeroy.

The NRCC has spent close to half a million dollars targeting those incumbents. 

The next round of IE ads rolled out from the DCCC will likely tell the story of how party strategists plan to build their midterm firewall in an attempt to retain the Democratic majority in the House.

To this point, the DCCC has run ads in 9 districts held by vulnerable Democrats — those of Reps. Bobby Bright (Ala.), Bill FosterBill FosterHouse GOP’s new challengers: Scientists mulling campaigns Dems crowd primaries to challenge GOP reps Lawmakers talk climate for Earth Day, Science March MORE (Ill.), Schauer, John Boccieri (Ohio), Leonard Boswell (Iowa), Betty Sutton (Ohio), Larry Kissell (N.C.), Glenn Nye (Va.) and Travis Childers (Miss.).

The NRCC has not reserved ad time in Sutton’s district, according to a strategist.

The committee has also spent big on two Democratic-held open seats, sending an early signal that Wisconsin’s 7th district and Michigan’s 1st will likely be the cornerstone of their plan to keep the House under Democratic control.

The DCCC’s first IE ad targeted Republican Sean DuffySean DuffyRight worries about Trump move on immigration House Republican 'looking forward to having Kid Rock in Congress’ GOP lawmaker breaks with Trump, says Confederate statues should come down MORE, who is running against Democrat Julie Lassa in the race to fill retiring Rep. David Obey’s (D-Wis.) seat. The second hit Dan BenishekDaniel (Dan) Joseph BenishekRepublican groups launch final ad blitz in key House battlegrounds Tea Party class reassesses record Michigan Republican to retire MORE (R), who is running against Gary McDowell (D) for the seat vacated by Rep. Bart Stupak (D-Mich.).

In all, the NRCC has run ads in 30 of the 55 districts it has reserved TV time in ahead of November, according to independent expenditure records filed with the Federal Election Commission.

The NRCC was also on the air Monday targeting Reps. Edwards, Childers, Spratt, Scott Murphy (D-N.Y.), Kirkpatrick, Allen Boyd (D-Fla.), Debbie Halvorson (D-Ill.), Joe DonnellyJoseph (Joe) Simon DonnellyGOP sees fresh opening with Dems’ single payer embrace Trump steps up courtship of Dems Trump having dinner with Schumer, Pelosi on Wednesday MORE (D-Ind.), Mike McIntyre (D-N.C.), John Adler (D-N.J.), Dahlkemper, Patrick Murphy (D-Pa.), Perriello, Baron Hill (D-Ind.), Bright and Rick Boucher (D-Va.).