WASHINGTON — The chairwoman of House Democrats' campaign arm said Monday that she won't seek the post again for the next Congress, days after her party's unexpected loss of seats in last week's election triggered recriminations among Democrats.

Illinois Rep. Cheri Bustos' decision to not seek a new term atop the Democratic Congressional Campaign Committee comes with party members upset and divided over why that happened. Their candidates widely outraised their Republican rivals in many races and Bustos' committee spent aggressively in GOP-held districts around the country in hopes of making their majority even larger.

Both parties and nonpartisan political analysts expected Democrats to pad the size of this year's majority by perhaps 15 seats. While they are on track to retain House control, seven Democratic incumbents were defeated and they'd ousted no Republican representatives, leaving it all but certain they will have a narrower hold on the chamber.

Also Monday, Rep. Hakeem Jeffries, D-N.Y., asked his fellow Democrats to give him another two years in one of his party's top jobs, leading the chamber's Democratic caucus. Jeffries is considered a top contender to succeed Speaker Nancy Pelosi, D-Calif., once she steps aside, and his decision was the latest indication that she so far faces no serious challenges for her post.

In a letter to his Democratic colleagues, Jeffries called for unity, saying, "We can only maximize our effectiveness on behalf of the American people if we have the gavel."

Even before Bustos' announcement, several Democrats said privately that she would have little support to retain her post, which is an elective position chosen by House Democrats. Her tenure included clashes with progressives angry that she moved to protect incumbents — including conservative Democrats — by denying contracts to political consulting firms that helped challengers in party primaries.

In a written statement, Bustos said her committee had achieved its "primary objective" of keeping House control. She said that with President-elect Joe Biden in the White House, she would focus on "exciting legislative possibilities in the years to come."

Pelosi said Bustos "shaped a mainstream message, mobilized effectively and attracted the resources to do so" and called her "a leader of great integrity and inspiration."

Bustos, 59, a four-term lawmaker, narrowly won her own reelection in a closely divided rural district she won by 24 percentage points two years ago. Her win came after an eleventh-hour $1 million expenditure for her by the House Majority PAC, which was resented by some Democrats. That committee is aligned with House Democratic leaders.

By Monday afternoon, Democrats' only gains were three GOP-held, open districts from which Republican lawmakers are retiring.

House Democrats currently have a 232-197 advantage, plus one independent and five vacancies.