Sen. Bernie Sanders (I-Vt.) said Sunday that Democrats should’ve done more to support the party’s candidate, James Thompson, during the special House election in Kansas last week.

“It is true that the Democratic Party should have put more resources into that election,” Sanders told host Jake Tapper on CNN’s “State of the Union.” “But it is also true that he ran 20 points better than the Democratic candidate for president did in Kansas.”

State Treasurer Ron Estes beat the Sanders-backed candidate by just 6 percentage points in a heavily Republican district.

Estes and Thompson were fighting for former Rep. Mike Pompeo’s (R) seat after President Trump tapped him to become the director of the CIA. Pompeo had won reelection by over 30 percentage points.

The Democratic Congressional Campaign Committee and progressive strategists have come under fire for not doing more to help Thompson win, while Trump and other top Republicans such as Vice President Pence and Sen. Ted Cruz (R-Texas) voiced support for Estes.