Paying attention to July polls for November ballot propositions is a bit like betting on pre-season NFL games: just because you can doesn’t mean you should.

Having said that, though, an online poll by the California Business Roundtable and Pepperdine University School of Public Policy has some mighty welcome news for Gov. Jerry Brown.

Sure, it’s good that his Prop. 30 tax initiative has a 56 percent to 39 percent lead in an admittedly self-selecting poll. And Team Brown likely is relieved to see that Molly Munger’s rival tax measure has its numbers almost reversed, with 35 percent in favor and 54 percent opposed.

But the most exciting news for the governor, not that you’d ever get him or his supporters to admit it, involves Prop. 32, which would bar unions from using payroll deductions to collect money for their political contributions.

According to the polling, the anti-union measure is way popular with voters right now, with 60 percent looking to stick it to labor and only about 29 percent looking to keep that campaign cash flowing.

That doesn’t mean Brown – or any other California Democrat, for that matter – wants to see the GOP-backed Prop. 32 win. Labor support, which includes buckets of cash, is a central part of Democratic campaigns at every level of California politics, from city council contests all the way to the top-of-the-ballot races for governor and the U.S. Senate.

Take away that labor money, or at least make it much, much harder to collect, and suddenly the chances for Republicans candidates in the state are looking a lot brighter in coming years.

But while Brown wants the labor forces to win in November, he’s probably not nearly so anxious to see them leading the polls in July. Bad news in early polls is like a bell in a firehouse, waking up everyone involved and warning them that ugly things may be happening outside.

In a state as blue as California, the key to victory for Brown’s tax initiative is to get every possible Democrat to the polls. While President Barack Obama’s name at the top of the ballot should help boost turnout, not even the most Pollyanna-ish Republican pundit believes Romney has a shot at the state’s electoral votes. With the president’s re-election already in the bag – at least in California – state Democrats might not be so motivated to show up at the polls come November

That’s where the labor folks come in. Sure, union people will be backing Brown’s tax initiative and walking precincts for Democrats because that’s what they do in California. But that’s for Brown’s initiative and Democratic candidates.

Prop. 32, on the other hand, is a threat aimed directly at California’s unions and the political clout they’ve worked so hard to gather in the state over the years.

As Samuel Johnson said a couple of centuries back, “When a man knows he is to be hanged in a fortnight, it concentrates his mind wonderfully.”

Ugly polls, even when they’re early and may be of questionable accuracy, will concentrate the minds – and November election efforts – of union leaders wonderfully, since their political lives are at stake.

Beat Prop. 32 and it’s more years of business as usual, with Democrats paying ever-so-close attention to labor concerns. Lose and union leaders are likely to be hearing “What have you done for me lately?” from their former compadres.

That’s a delightful scenario for Brown, since the voters the unions will be working overtime to bring to the polls to bash Prop. 32 are the same ones who will stay to vote for his tax measure. So the worse the numbers on Prop. 32 look, the more time, energy and money labor will spend on statewide get-out-the-vote efforts and the better it works out for the governor.

So Brown, the ex-Jesuit seminarian, is likely paraphrasing St. Augustine’s ancient prayer for chastity before he goes to bed each night:

“Lord, grant the unions victory … but not yet.”

John Wildermuth is a longtime writer on California politics.