California: Low Totals Explained

​All California Senate race polling has consistently shown Sen. Dianne Feinstein (D) well below 50%, but she runs beyond the polling margin of error against her Democratic general election opponent, state Sen. Kevin de Leon (D-Los Angeles).  
 
The recent YouGov/Stanford University survey (10/10-24; 2,178 CA voters) is consistent with other statewide political studies but exhibits an interesting side note.  While the ballot test shows Sen. Feinstein leading just 36-29%, it reveals that 19% of the respondents say they will vote for neither of the two candidates.  This number likely points to Republicans who are planning to skip the double-Democratic Senate race, just as they did in 2016 when then-Attorney General Kamala Harris defeated then-Rep. Loretta Sanchez (D-Garden Grove). 
 
In that election, 1.3 million more people voted in the final statewide ballot proposition that banned individual-use plastic bags than for US Senate, for example.  This high number of people skipping the Senate race and then returning to vote the rest of the ballot were Republicans not wanting to make a choice in the double-Democratic campaign.