Lincoln wins Arkansas runoff

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.

With 80 percent of precincts reporting, Lincoln had 51.7 percent of the vote to Halter’s 48.3 percent.

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 Hussein ObamaOvernight Energy: Dems ask Pruitt to justify first-class travel | Obama EPA chief says reg rollback won't stand | Ex-adviser expects Trump to eventually rejoin Paris accord Overnight Regulation: Trump to take steps to ban bump stocks | Trump eases rules on insurance sold outside of ObamaCare | FCC to officially rescind net neutrality Thursday | Obama EPA chief: Reg rollback won't stand Ex-US ambassador: Mueller is the one who is tough on Russia MORE and Bill ClintonWilliam (Bill) Jefferson ClintonShould the Rob Porter outcome set the standard? Make the compromise: Ending chain migration is a small price to legalize Dreamers Assessing Trump's impeachment odds through a historic lens 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!"

Lincoln’s 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. 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 (Bob) MenendezJustice Dept intends to re-try Menendez in corruption case DACA is neither bipartisan nor in America's interest Senate DACA deal picks up GOP supporters MORE (N.J.), chairman of the Democratic Senatorial Campaign Committee, said in a statement.

She faces Republican Rep. John BoozmanJohn Nichols BoozmanSenate Republicans call on Trump to preserve NAFTA Dems go on the attack during EPA chief's hearing Bipartisan group of senators ask Trump to fund broadband in infrastructure plan 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.