For those who have been waiting for a clear-cut example of how California’s top-two primary system could make a difference in the electoral landscape, the case in point is here: Dianne Feinstein’s re-election campaign.

Senator Feinstein’s announcement via Twitter that she will seek another term in Washington came as no surprise.  Neither did the predictable outcry from the Democratic Party’s left, arguing that she should step aside and make way for a younger, “more progressive” candidate.  The electoral math, however, tilts heavily in Senator Feinstein’s favor.

Silicon Valley Democratic Congressman Ro Khanna has called for a progressive challenger to take on Feinstein, but, notably, didn’t volunteer to take the challenge himself.   The Senator’s most talked about, potential primary challenger is State Senate President pro Tempore Kevin de Leon—an ambitious politician, who is term limited and has no obvious political place to land.   De Leon, however, is hardly a household name and would face a daunting fund-raising climb, since none of his state war chest can be used in a federal race.  Nonetheless, De Leon has been critical of Feinstein for not being tough enough on Donald Trump and has been making loud noises on the immigration issue and California’s “sanctuary state” status. Just recently, post-Las Vegas, de Leon challenged Feinstein on one of her signature issues—gun control, criticizing her for remarking on TV that no law could have stopped the shooter.

Probably, Senator Feinstein’s only real electoral vulnerability is her age.  An early September poll by Berkeley’s Institute for Governmental Studies (done well before Feinstein’s actual announcement) found that, although California registered voters, gave the Senator a 50% job approval rating, only a plurality (45%) of voters said they were inclined to support her for re-election and 41% said they were not inclined.

However, that is a lot different than voting against her now that she is running and will be facing real live opponents with their own vulnerabilities.

Despite the protestation of the Berniecrats, Senator Feinstein’s record shows few weak points.  She has been a consistent and outspoken proponent of tough guns laws.  She has stood up against President Trump on immigration, health care, the environment and judicial appointments.  Even in the minority, she has clout as ranking member of the Senate Judiciary Committee and member and former Chair of the Senate Intelligence Committee.  She remains a visible player in the Congressional investigation of Russian campaign mischief. Her seniority is a big plus in a legislative body that rewards longevity and her status has proven valuable as California competes for federal dollars. And there is that question out there about whether voters might look for experience in their Congressional leaders, to check what GOP Senator Bob Corker has described as a White House malfunctioning as “an adult day care center.”

A relative moderate, not given to bombast, Senator Feinstein took major flak for saying that Donald Trump could still be a good president if he would learn–but she didn’t predict he would.  Bernieworld is also upset that Senator Feinstein didn’t jump on the single-payer health care express along with a number of Democratic presidential wannabees, who have endorsed Bernie Sanders’ “Medicare for All” proposal.  California’s senior senator is not geared to play Don Quixote and advocate for a bill that is going nowhere–at least until there is another Democrat in the White House.

Perhaps Senator Feinstein would be vulnerable in a Democratic Primary, but California doesn’t have closed primaries anymore—except for Presidential elections.  The top-two primary was intended to increase the possibility that more moderate candidates would prevail.  All the state’s U.S. Senate candidates, regardless of party, will appear on everybody’s primary election ballot and the top two vote-getters will run off in the November election.  It won’t be enough for any Democratic Senate candidate to win the hearts and minds of Democratic voters—Republicans and independents will also have a say.  Even if Senator de Leon—or another Democratic contender– succeeds in galvanizing a liberal majority, it is hard to see Republicans and centrist independents preferring him to Feinstein. The IGS poll shows a lower percentage of younger voters (18-25 yrs.) are inclined to support Feinstein than are other age groups (but young voters generally lag in turn-out).

If, by some chance, a Republican manages to get into a November run-off, Feinstein should have little trouble uniting the Democratic base and scoring heavily with No Party Preference voters.

Of course, this election, like every other election, will ultimately come down to turn-out—how large it is, whose voters’ turn-out, what the demographic, economic, ethnic, and ideological portrait of the voters who do turn out is —and how effective the candidates are in reaching out to build, expand and motivate a base.

And, although the results of the 2016 Presidential election should have taught us never to say “Never” in politics, in next year’s California U.S. Senate race, this is how the scenario is likely to play out—at least as of today: The electoral arithmetic is on Senator Feinstein’s side.