With the results (mostly; California can take weeks to tabulate all the results) in for the June 3 primaries, more than half of American voters have had a chance to vote in primaries this year--though not very many have taken advantage of it.

My first observation is that turnout has generally been low, and especially among Democrats. In some cases that is because Republicans have had seriously contested primaries in high-visibility statewide races and Democrats have not; that may have accounted for the higher Republican than Democratic turnout in Iowa this week, for example.

But it doesn't account for the higher Republican turnout in Montana, where appointed Sen. John Walsh had visible primary opposition and Republican Congressman-at-Large Steve Daines didn't in his primary. Nor does it account for Alabama, where neither party had a seriously contested statewide primary and Republican turnout was 2.4 times higher than Democratic turnout. In Mississippi, Republican turnout was 3.7 times higher than Democratic turnout, but there the Republicans had a high-visibility Senate primary and Democrats didn't. Most Alabamians and Mississippians who have been voting Democratic in general elections are black, and I take the low Democratic turnout in both states as an indication that interest in voting is significantly lower among blacks this year than it was in 2008 and 2012.

A second observation: Most Republican incumbents have been surviving primary challenges, but not quite all, and some by surprisingly narrow margins.

The big story Tuesday in this regard was the Mississippi Senate primary, in which incumbent Thad Cochran narrowly trailed state Senator Chris McDaniel (by 49.6 percent to 48.9 percent); since neither got an absolute majority, there will be a runoff June 24. You can expect many fireworks until then. Among incumbent Republicans, Cochran was particularly vulnerable: He is in his 36th year in the Senate, after six in the House; he hasn't had a serious electoral challenge in at least 30 years; he turns 77 this year; he has been a quiet appropriator at a time when Republican primary voters like loud protests and dislike earmarks and pork barrel spending. Spearheading the drive for him is former governor and Republican National Committee Chairman Haley Barbour, who attacks McDaniel for opposing his successful tort reform legislation.

The results were also close in two House primaries that did not win national attention.

In Mississippi 4 incumbent Steve Palazzo apparently narrowly topped 50 percent to avoid a runoff against his predecessor Gene Taylor, who got 44 percent. Taylor was first elected as a Democrat in a 1989 special election and continued to win as a Democrat until he was beaten by Palazzo in 2010, by which time his voting record was very much more conservative than that of other House Democrats.

In New Jersey 7 incumbent Republican Leonard Lance won by only 54 to 46 percent. That leads me to wonder whether Steve Lonegan, who ran unsuccessfully for senator in the 2013 special election and twice lost primaries for governor, might have done better to have run in this district against an incumbent than he did running for the open seat in New Jersey 3, where he lost the primary by 60 to 40 percent to state Sen. Tom MacArthur. Either race would have required Lonegan to move from his home turf in North Jersey, where he was once Mayor of the town of Bogota north of the Jersey Meadows, and New Jersey 7, which spreads across the state well north of Trenton, is closer geographically to Bogota than Jersey 3 in South Jersey.

Finally, some observations on our largest state, California, in its second electoral cycle with a system where the top two in the primary go on to the general election. Its advocates envisioned that the system would somehow produce an election with more moderates and fewer left-wing Democrats and right-wing Republicans, but there has been little sign of that as yet in congressional or legislative races. In the governor’s race, however, California Republicans, like those in many earlier primary races, preferred a more moderate or at least modulated candidate to one inclined to stand up on a chair and yell, “Hell, no!”

Assemblyman Tim Donnelly, given to provocative if not downright foolish statements, got about 15 percent of the statewide vote, while former investment banker and Troubled Asset Relief Program administrator Neel Kashkari got about 19 percent. There was some late advertising for Kashkari, who is of Indian descent; he is obviously a much more presentable candidate than Donnelly would have been. Incumbent Gov. Jerry Brown got about 54 percent of the vote, suggesting a fairly easy win for him in November, but not perhaps the landslide that many have expected.

What we do see in the primary results is a huge continuing schism between coastal California -- heavily Democratic from Monterey through the San Francisco Bay Area and up to marijuana-growing Mendocino and Humboldt Counties -- and the Central Valley, which seems increasingly Republican, as environmentalists continue to choke off the water needed by America's potentially most productive agricultural land.

So in the Sacramento suburban California 7, Democratic incumbent Ami Bera won just 47 percent of the vote and the Republicans totaled over 50 percent. In top-two primary systems an incumbent’s (or his party’s) share of the vote in the primary has been a good forecast of the general election, as in Washington state in 1994. Some analysts point out that Democrats tended to do better in November 2012 than they did in that year’s primary. That may be a replicable phenomenon, or it may have been due to enthusiasm either for Barack Obama or (among young voters) for Gov. Jerry Brown’s ballot proposition to raise taxes and spend it on college subsidies. We’ll see; if I were Ami Bera, who beat incumbent Republican Dan Lungren in 2012, I would be very concerned.

I would be concerned as well if I were Jerry McNerney, who got about 50 percent in California 9, partly in the Valley but partly also in the Bay Area. Or Jim Costa, who got only 44 percent in California 16, which is entirely in the Central Valley. In contrast, Republican Central Valley incumbents did very well: Jeff Denham got 57 percent in California 10 and David Valadao got 64 percent in California 21. Note that California 16 and 21 are Hispanic-majority districts, with very low overall turnout. That suggests lack of interest or lack of support of Democrats by Latinos. Which is understandable, given the Valley's high unemployment rate and the coastal environmentalists' successful efforts to keep water--and therefore jobs--out of the Valley.

In Southern California there are also signs of trouble for incumbent Democrats. Lois Capps received about 44 percent in Santa Barbara-centered California 24 and Julia Brownley received about 46 percent in Ventura-centered California 26. And in North County San Diego California 52, Scott Peters received only 42 percent. The Republican nominee there is former San Diego Council member Carl DeMaio, who is gay and has run a TV ad showing him holding hands with his partner.

Encore: Congratulations to Jeff Bell, nominated for U.S. Senate in New Jersey on Tuesday as he was in 1978, 36 years ago. That year Bell beat incumbent Clifford Case, a liberal who generally voted with Democrats, by calling for supply-side tax cuts. He lost the general election 54 to 46 percent to Democrat Bill Bradley; but he helped influence Bradley to support the preference-cutting, tax-rate-cutting proposal which was the basis for the tax reform act of 1986. New Jersey is a more Democratic state now than it was in 1978, and Bell is clearly an underdog in his race against Cory Booker, an incumbent since his victory in the October 2013 special election to replace the late Frank Lautenberg. If he loses to Booker, it will be the second time he has lost to a former Rhodes Scholar.

Bell is not the only candidate to return to congressional politics after a long absence: liberal Democrat Rick Nolan, elected in Minnesota 6 in 1974, 1976 and 1978, returned to politics and was elected in Minnesota 8 in 2012. American life is full of second acts.