The answer is, a lot — although it depends. But before we tell you why or give you examples, you’ll have to put up with a bit of a civics lesson. Purists will tell you that there’s no such thing as a county line and that any candidate can create a line in any county. But there is such a thing as the county line. The confusion arises because the line doesn’t officially belong to the county party. It belongs to the campaign manager for the party’s designated candidates for freeholder. That is, of course, merely a technical problem. It’s a basic tenet of County Chairmanship 101 that the Chair picks himself or herself or someone very close to be the campaign manager for the party’s freeholder candidates.

And while it’s true that any statewide candidate can create an alternative line by filing running mates, who have the same campaign manager, to run for freeholder, that maneuver takes some organization – and nerve. You have to find candidates willing to cross the powers that be in the county. You have to gather signatures (and party organizations are adept at challenging rivals’ petitions successfully). And, if you succeed, all you get is a list of names on the ballot as long as the organization’s list. It doesn’t get you the organization’s voters or money.

That’s the civics lesson, so what’s the practical effect of having the support of a county party? On the Democratic side, it’s all but decisive. In Tuesday’s gubernatorial primary, for example, Phil Murphy had the support of all 21 county parties. He carried 20 of them. The one he lost was Salem County, where John Wisniewski prevailed over him by three votes (861-858), doesn’t have a physical line. It’s a seemingly insignificant matter, but, if those numbers hold through the official tally, it will mark the first time a candidate in a statewide Democratic primary – for Governor or U.S. Senator — won a county without party support  since Michael Murphy (no relation to Phil) carried Hunterdon, Mercer, Morris, Sussex, and Warren – the first three pf which do have a physical line — while finishing third in the 1997 gubernatorial. (For a short time after that primary 20 years ago, there was talk of a Western Alliance of the counties Murphy carried and the decisive effect they could have on Democratic primaries, but that’s another story.) The lesson is that having the lines in the areas rich in Democratic votes– Bergen, Essex, Hudson, Middlesex, and the seven-county South Jersey monolith – is all that matters.

The cynical among you may say that it’s possible for money to trump lines. But the truly cynical among you will recognize that you can’t attract donors if you have no lines, and, if you have personal wealth and you spread it around wisely, it will bring you lines.

For the Republicans, the line, while by no means insignificant, is less decisive. One illustration of how potent a Republican line can be came in the 2000 U.S. Senate primary, when Ocean County gave Bill Gormley a 10,000 vote margin over Bob Franks. That was more than wiped out, however, by Union’s 8,000-vote margin and Burlington’s 6,700-vote edge for Franks.

A year later, however, Bret Schundler negated the power of the lines when he triumphed over Franks in the 2001 gubernatorial primary. Schundler had only one line, his home county Hudson’s, but he carried 14 other counties as well on his way to collecting 55 percent of the vote. That’s because Schundler was the darling of the conservative movement, a potent force, unlike anything in the Democratic Party, in the Republican electorate, when harnessed. (If you’re not convinced of that, take a look at the 2009 Republican gubernatorial primary. Steve Lonegan, who had no lines, carried three counties (Salem, Sussex, and Warren) and got almost 141,000 votes statewide, 38 percent of the total. Because there is no line in those counties and party officials can’t, therefore, weed them out, movement conservatives do well there.)

The next gubernatorial primary, in 2005, was a free for all and helps account for the conventional wisdom that lines are less important for Republicans. Doug Forrester won the nomination in an eight-candidate race in part because he won in Ocean County even though Rob Schroeder had the line there. On the other hand, Forrester narrowly lost Union County, even though he had the line, to Bret Schundler, who also won in Passaic County even though Paul DiGaetano had that line.

Tuesday night’s primary is again instructive. With no movement conservative in the race, it came down to lines and money. Kim Guadagno won decisively statewide, but she lost one county where she had the line (Gloucester, by 20 votes) and one county that has no ballot line but whose party supported her (Salem, by 123 votes). On the other hand, she won two counties (Mercer, by 205 votes, and Middlesex, by 772 votes) where Jack Ciattarelli had the line. As with the Democrats, it’s which lines you have. The monoliths here are Bergen, Monmouth, and Ocean, which she carried by 6,000, 8,000, and 12,000 votes, respectively. If you have party support in those three places, you’re well on your way to victory.

The wildcard in Republican primaries is Morris County. There’s no party line there not because of the history of how ballots were printed for the old punch card voting systems but because the party doesn’t want one. (Back in the 1970s, the Republican County Committee voted on whether to institute a line. When the measure passed by one vote, then-Chairman Alex DeCroce overruled the outcome on the grounds that it was too important a matter to be decided by so slim a margin. Nobody has had the temerity to broach the subject since.) This makes for crazy, eat-your-own primaries in races for county offices, especially for freeholder, but it also makes the county a bellweather. In this century, the only losing statewide candidates who carried Morris were favorite sons Joe Pennacchio (for U.S. Senate in 2008) and John Murphy (for Governor in 2005). For the record, Guadagno carried Morris by 1,300 votes.

The lessons to be learned from all this: If you want to run for Governor or U.S. Senator, never run against a fabulously rich opponent; make nice with all 21 county Chairs, but make even nicer with the ones whose counties have the most votes in your party; and, if you’re a Republican, spend a lot of time in Morris County.

Nick Acocella is the founding editor of Politifax.