This election year we've been hearing a lot about the Trump effect—the impact of the Republican presidential nominee, Donald Trump, on races down the ballot.
Hoping to capitalize on Trump's struggles in the presidential race, Democrats have set their sights on vulnerable House Republicans to target for defeat.
In California, that focus has narrowed in on Congressman Darrell Issa (R-Vista). He's the eight-term incumbent from the 49th District, encompassing parts of San Diego and Orange Counties, and Camp Pendleton.
It's a district that, in years past, was a pretty unassailable Republican stronghold. So much so, Issa has not had to run an election campaign since he was first elected to the House in 2000. But this time around, things have changed.
This year, the race between Issa and his Democratic challenger Doug Applegate has become a close one. Applegate is a retired Marine colonel-turned-lawyer. This is his first foray into politics.
Michael Smolens, government editor at The San Diego Union-Tribune, says everyone was taken by surprise when Applegate finished only about five percentage points behind Issa in the June primary.
"The Democratic Party didn't necessarily recruit Doug Applegate," Smolens says. "I don't think they knew much about him. But they certainly embraced him after the primary."
One big factor contributing to Darrell Issa's vulnerability this time around is his support of Donald Trump.
Smolens says Issa's enthusiastic and early endorsement of the Republican presidential candidate has made him the "poster boy for Trump shaming."
But that still doesn't tell the whole story.
The fact that the 49th District has become less solidly Republican is also a contributing factor to Issa's struggles. Another is the criticism that Issa became too focused on national issues and wasted time and money on investigations of the Obama administration while he was chair of the House Oversight Committee.
As for what this all might mean come Election Day, this month the non-partisan Cook Political Report moved the 49th Congressional District to a "toss up." It's the first time that's happened since Issa was elected in 2000.
Click the blue audio player above to hear the full interview.