First lady Michelle Obama will make an appearance for California Sen. Barbara Boxer (D) in the closing stages of her race against Republican Carly Fiorina.

Obama is set to appear with Boxer in Los Angeles on Oct. 27 — five days before the midterm election. Obama was nicknamed the "closer" during the 2008 presidential election that saw her husband win the White House.

"We're thrilled that in the closing days of the campaign, the First Lady will be coming to California to campaign with us and urge Californians to go to the polls," Rose Kapolczynski, Boxer's campaign manager, said in a statement.

Obama's popularity took a hit this summer when conservative commentators criticized her for vacationing at a lavish resort in Spain. But she remains well-liked by the Democratic base that party leaders will be looking to motivate.

Fiorina's camp said Obama's visit is a sign Democrats are "nervous" about Boxer.

"National Democrats are clearly so nervous about Californians' distaste for Barbara Boxer and her nearly three decade political career of supporting job-killing policies and failing the people of California that they are forced to send in reinforcements to try and salvage the only job Boxer cares about -- her own," Andrea Saul, a spokeswoman for Fiorina, said in a statement. 

--Updated at 4:08 p.m.