A new poll from End Citizens United found the race for California’s 45th District essentially tied, as Democrats try to unseat two-term Republican Rep. Mimi Walters in their effort to win back the House. 

Forty-eight percent of respondents backed Democratic challenger Katie Porter while 47 percent supported Walters in the survey conducted by GBA Strategies and shared first with Roll Call. 

Walters is one of seven California Republicans running for re-election in districts that backed Hillary Clinton in 2016. She carried the Orange County-based 45th District by 5 points. Democrats believe the historically Republican stronghold is a midterm battleground this year.

Inside Elections with Nathan L. Gonzales rates the race a Toss-up. 

Porter, a law professor at University of California, Irvine, has the endorsement of End Citizens United, which backs candidates who favor a campaign finance overhaul.

The group spent to boost Porter in her primary. She is one of many Democratic candidates this cycle rejecting corporate PAC money.

“Katie’s reform-focused campaign offers voters a chance to elect a representative who has been fighting against powerful interests over her career,” said Tiffany Muller, president of End Citizens United. “We’ll continue to get the word out about Katie, and her commitment to putting people first.”

President Donald Trump’s favorability rating in the 45th District was under water in the poll, with 30 percent rating him favorably and 52 percent viewing him unfavorably. Forty-five percent approved of Trump’s job as president, while 51 percent disapproved.

GBA Strategies surveyed 400 likely voters via live telephone interviews from Sept. 20-23. The pollsters used landline and mobile phones. The poll had a margin of error of 4.9 percentage points. 

Watch: Ros-Lehtinen, Gutiérrez Talk Election 2018 With Roll Call