David Axelrod, President Obama's top strategist, will headline a fundraiser for House candidate Tammy Duckworth in Illinois, according to the Chicago Sun-Times.

Axelrod's appearance is the latest sign that Duckworth has the institutional backing of Democrats in her primary race against former Obama adviser Raja Krishnamoorthi. Sen. Dick Durbin (D-Ill.) has already endorsed her.

This is not the first time senior Democrats have backed Duckworth in a contested primary. In 2006, then-Democratic Congressional Campaign Committee Chairman Rahm Emanuel convinced the Iraq War veteran, who lost both of her legs in a helicopter crash, to run for a Republican-leaning suburban Chicago district even though Christine Cegelis, the 2004 Democratic nominee who had nearly beaten then-Rep. Henry Hyde (R-Ill.), was already in the race. In 2010, members of the Obama administration tried to get her to run for Obama's old Senate seat, which Sen. Mark Kirk (R-Ill.) eventually won.

Axelrod said that he has "deep admiration" for Krishnamoorthi but that Duckworth's unique life story deserves his support. "I think it is going to be an amazing day when Tammy walks out on the floor of the House. And when they debate these issues, some of these fundamental issues, she is going to have a moral authority that very few people have," he said. "Her voice is one that will really resonate on the floor of the Congress."

Whichever Democrat wins this primary will likely win the general election — the new district was drawn by Democrats in the statehouse to lean Democratic.