"Jiu-jitsu" races and gender gap may determine 2018 House control

Last Updated Jun 3, 2018 2:20 PM EDT

CBS News Political Correspondent Ed O'Keefe sat down with Anthony Salvanto, CBS News Elections and Surveys Director, to break down what to look for as the midterm elections near this November for our first edition of the Battleground Briefing, a wonky deep-dive into the numbers driving the unique CBS News/YouGov Battleground Tracker model.

Will Republicans keep control of the House?

If the election were held today, the CBS News/YouGov Battleground Tracker reports a likely toss-up for which party would have the majority. Democrats would most likely get 219 seats the model reports, with a nine seat margin of error. 

This gap between Democrat and Republican seats will likely continue to fluctuate throughout the midterm election season, as different issues energize voters. 

The specific issues candidates decide to run on might swing the election in their favor. At a national level, most Republicans want to hear a lot about are immigration, jobs and wages, and health care while Democrats want a focus on health care, income inequality, education and teacher salaries, and jobs, the Battleground Tracker reports.

A prime example of how seats may flip political parties are the races in southern California.

Welcome to the "jungle primaries" of California

In the south of the sunny Golden State, a "jiu-jitsu race" is brewing, according to O'Keefe. California's primary system awards the top two finishers a chance to compete in the general election, regardless of party, potentially shutting out some parties entirely come November.

Democrats assert there are 10 districts in southern California where they believe they can flip seats from either a Republican incumbent, or a seat vacated by a retiring Republican. Democrats "believe that because Hillary Clinton won these districts in 2016 that they may have shot here of potentially winning them," said O'Keefe.

Democrats' excitement has translated to a crowded primary in some districts, with several Democrat candidates trying to out-maneuver each other for the same seat. This could splinter the Democrat's base, opening a door for Republican candidates potentially block out Democrats.

So while Democratic primary votes may not be able to guarantee a win for the control of the House in the fall, Salvanto warned, in some races "they could lose it."

A big gender gap in battleground states

Democrats have a 14-point advantage among women, and Republicans lead among men by five points, the Battleground Tracker reports.

Gender issues, like whether or not women feel as if the president respects them, could be used as motivation to draw out new voters who do not usually vote in the midterms, according to Salvanto. 

And yet, "we're old enough to remember 2016 [election] where Democrats were going to win over all of these voters and they didn't do nearly as well as they wanted to so it's clear that this is a group that could swing," Salvanto told O'Keefe.

Tune in throughout the midterm election season for updates to our CBS News/YouGov Battleground Tracker and new editions on CBSN of our post-game show, the CBS News Battleground Briefing. 

The CBS News/YouGov Battleground Tracker is run by the CBS News' Election and Survey Unit team: Anthony Salvanto, Jennifer De Pinto, Kabir Khanna and Fred Backus. Through a unique model, it will report an estimated seat count throughout the 2018 midterm elections.