Sen. Blanche Lincoln (D-Ark.) survived a hard-fought primary against Democratic challenger Bill Halter.
The Associated Press has declared her the winner in Tuesday's runoff.
The two-term senator was written off by Washington insiders, who predicted she’d become the fifth lawmaker to fall during this cycle’s primary season.
She didn't get a majority in the May 18 primary.
Backed by unions and progressive advocacy groups, Halter had the
momentum going into Tuesday’s vote. But Lincoln had the support of two
Democratic presidents — Barack ObamaBarack ObamaObama reflects on his legacy as presidency comes to an end Confirm Gary Richard Brown for the Eastern District of New York Megyn Kelly: Trump and First Amendment 'not a beautiful match' MORE and Bill ClintonBill ClintonFormer Labor secretary to Trump: Stop being 'petty, thin-skinned and vindictive' Why Dana Rohrabacher should be Trump's Secretary of State Would it be legal for Trump to give his son-in-law a White House gig? MORE — and much of
the Democratic Party establishment in Arkansas.
Clinton rallied supporters for her in Little Rock, and the Lincoln campaign used footage from the event in a campaign commercial.
In an e-mail to supporters Tuesday night, Lincoln said Clinton called her and said: "Blanche, you're the new Comeback Kid!"
victory is a major blow to labor and progressive groups who poured
millions into Halter’s campaign. It may serve to check their aggression
against centrist Democrats, who were likely worried about what a
Lincoln loss could mean for their own electoral fortunes.
Unions and their allies spent more than $6.5 million to take down Lincoln and turn Arkansas into yet another symptom of a national anti-incumbent mood.
The Service Employees International Union (SEIU) spent more than $3 million on the race, according to Federal Election Commission (FEC) records, while the American Federation of State, County and Municipal Employees spent more than $1.5 million.
The AFL-CIO sent staff from its Washington office to help Halter supporters get to the polls, as did Working America, its community affiliate.
Working America’s 41 paid organizers in Arkansas made 315,000 phone calls and knocked on 120,000 doors, canvassing voters in 27 cities and 17 counties in the state, according to spokeswoman Alison Omens.
The group also spent more than $1.3 million on ads and was been in Arkansas since the healthcare fight, when it urged constituents to press Lincoln to support the public option.
MoveOn.org and the Progressive Change Campaign Committee also helped raise millions for Halter. The PCCC even took credit for running his field program.
Democrats were quick to congratulate Lincoln on the win.
“Blanche has proven once again she is a true independent voice for the people of Arkansas, but she is also a fighter for what she believes in and will never stop standing-up for her convictions or for her state,” Robert MenendezRobert MenendezThe right person for State Department is Rudy Giuliani Warren, Menendez question shakeup at Wells Fargo Democrats press Wells Fargo CEO for more answers on scandal MORE (N.J.), chairman of the Democratic Senatorial Campaign Committee, said in a statement.
She faces Republican Rep. John BoozmanJohn BoozmanArk., Texas senators put cheese dip vs. queso to the test Deficits could stand in the way of Trump's agenda The untold stories of the 2016 battle for the Senate MORE in the Nov. 2 general election.
— Kevin Bogardus contributed to this report.
— This post was updated at 11:21 p.m. and 11:50 p.m.