Senate Democrats are starting the 2018 election cycle $20 million in debt, which will likely make it even more difficult for them to retake the Senate in two years.

The Democratic Senatorial Campaign Committee concluded the post-general election fundraising period, which ended Nov. 28, with $20 million in debt and just $3.5 million in the bank.

The Republicans' Senate campaign arm, the NRSC, also finished the 2016 election cycle with a lot of debt — $18 million. But the NRSC also ended with $8 million on hand.

Senate Republicans spent their money holding the majority, winning tough races in Florida, Indiana, Missouri, North Carolina, Pennsylvania and Wisconsin, losing seats to the Democrats in only two states: Illinois and New Hampshire.

The DSCC's large debt means the group will have to use money raised in 2017 and 2018 to pay down debt from 2016, leaving them less to invest in the difficult races they are expected to face in 2018.

And many difficult races are expected. Republicans will only have a two-seat majority in the Senate next year, but Democrats will be defending more seats than Republicans in 2018, which increases the chances that the GOP will be able to pick up a few seats.

Democrats face a daunting Senate map, with few Republican targets and several vulnerable members of their party up for re-election in states Trump won. They include: Florida, Indiana, Michigan, Montana, North Dakota, Ohio, Pennsylvania, West Virginia and Wisconsin.

The DSCC out-raised the NRSC overall from January of 2015 through Nov. 28, bringing in $122 million to the NRSC's more than $80 million.

Under incoming Chairman Chris Van Hollen of Maryland, the DSCC this week hired Mindy Myers to serve as executive director. Myers' previous employers include President Obama's 2008 campaign and Sen. Elizabeth Warren, D-Mass.

"She has the unparalleled experience of running successful Senate campaigns," Van Hollen, an outgoing member of the House, said about Myers, in a statement.

Sen. Cory Gardner of Colorado is the incoming NRSC chairman. His chief of staff and 2014 campaign manager, Chris Hansen, is taking over as executive director.