The House Democratic campaign arm on Wednesday released the second round of candidates named to its "Red to Blue" program, adding to the party's list of top challengers ahead of this fall's midterm elections.

Candidates added to the list include Debbie Mucarsel-Powell, who is challenging Rep. Carlos Curbelo (R-Fla.); Dean Phillips, who is vying to unseat Rep. Erik Paulsen (R-Minn.); Brad Ashford, who is seeking a rematch against Rep. Don Bacon (R-Neb.); Kathy Manning, who is challenging Rep. Ted Budd (R-N.C.); Mikie Sherrill, who would challenge Rep. Rodney Frelinghuysen (R-N.J.); Max Rose, who is hoping to defeat Staten Island-based Rep. Dan Donovan (R-N.Y.); and Salt Lake County Mayor Ben McAdams, who is running for Rep. Mia Love's (R-Utah) seat.

The seven Republicans are all considered to be vulnerable, with Frelinghuysen and Bacon representing seats seen as toss-ups by the Cook Political Report.

The Red to Blue program, from the Democratic Congressional Campaign Committee's (DCCC), program will provide the candidates with fundraising and organizational support. The total number of Democrats backed by the program comes to 18. Democrats need a net gain of 24 seats to take back control of the House.

"Candidates are our best asset, and we will continue to do everything possible to help them build strong campaign infrastructures, energize the grassroots, and raise the resources needed to spread their message," said Rep. Ben Ray Luján (N.M.), chairman of the DCCC.

Mucarsel-Powell unsuccessfully ran for a state Senate seat in 2016 and has garnered an endorsement from EMILY's List, a group that aims to elect women who support abortion rights to office. Democratic nominee Hillary Clinton carried Curbelo's South Florida district by more than 16 points in the 2016 presidential election.

Phillips, a wealthy businessman, faces a crowded Democratic primary battling for the right to take on Paulsen in his suburban Minnesota district. Clinton also won this district by 9 points.

Ashford, who narrowly lost his Omaha-area seat in 2016, which Trump also narrowly carried, is hoping for a comeback in 2018. A president's party typically loses House seats in the midterms, giving him hope.

Sherrill, a retired U.S. Navy helicopter pilot and former federal prosecutor, also faces a contested primary to take on Frelinghuysen, the chairman of the House Appropriations Committee. Trump narrowly won the district, but the GOP tax bill could hit the area hard by limiting the allowed deduction for property taxes. Frenlinghuysen voted against the bill.

Manning's bid to take out Budd is a steeper challenge for Democrats. Trump carried it by more than 9 points in 2016.

Similarly, Trump won Donovan's district by double-digits, creating a challenge for Rose, an Army veteran. Donovan, however, faces a primary threat himself in former Rep. Michael Grimm (R), who is seeking a comeback after leaving the House and serving a prison term for tax evasion.

Love has been a frequent target for House Democrats, but she easily won reelection in 2016.