The latest ad from Governor Schwarzenegger's campaign has a clear message: if you're opposed to a tax increase, vote yes on Proposition 76. But when you examine the way Prop 76 would impact the state budget process, you're likely to conclude that the ad is a pretty big stretch.

The ad features three "average" people sarcastically asking for a tax increase, higher state spending, and modifications to the property tax initiative Proposition 13.

"This is how Sacramento thinks we think," says the narrator. The ad ends with a plea to "Say yes to 76, say no to a tax increase next year."

While Schwarzenegger may oppose a tax increase next year, Prop 76 does not prevent him from changing his mind.

New tax revenues would simply be subject to the Prop 76 spending cap. In other words... the initiative only limits how much money is spent, not how much money is collected.

Legislators and the governor would still be free to raise (most) taxes any time they want. If the Prop 76 spending cap is calculated to be higher than revenues, then those new tax dollars could be spent immediately.

The only impact on a tax hike comes if state spending is already maxed out under the Prop 76 spending cap. Even then, a tax hike would be allowable; Prop 76 would simply force the new dollars to be held in reserve.

The ad's implied message about tax increases is even more intriguing when you consider it has been debunked by none other than Schwarzenegger himself. At last week's televised forum in the Bay Area, the governor argued that Prop 76 wouldn't force a budget deficit to be solved through cuts alone-- that tax hikes could still be part of the solution.

The ad also implies that Prop 76 would restrict current state spending. But the measure would probably not force a lower level of state spending next year-- that's the assessment of both the non-partisan Legislative Analyst and the governor's own outgoing finance director, Tom Campbell.

In an interview earlier this month, Campbell told me that he believes the first forced restraint on spending under Prop 76 probably wouldn't happen for another few years.

As for the issue of Prop 13, the legendary "third rail" of state politics... Prop 76 offers no long-term protections of the property tax initiative. If lawmakers or voters decide to modify Prop 13 in the future, Prop 76 will play no part in that decision.

You can watch the ad here.