It’s a governor’s job to play the role of adult regulator and not give adolescent state legislators all the pocket money they want. Otherwise they would break the family bank.

All of California’s modern governors have served in this role, often in different ways and often with relish.

Many, especially Republicans, have liked to use their blue pencil and mark individual spending items from the annual state budget before signing it. That’s a powerful power enjoyed by California governors that American presidents don’t even have.

Gov. Ronald Reagan harbored the veto over the line item and often complained about not having the tool as president.

However, Gov. Gavin Newsom almost never picks up his blue pencil. He barely touches a spending plan before signing what he sent through the Democratic-controlled Legislature. That’s because he and legislative leaders already negotiated the final version of the budget before lawmakers approved it.

What Newsom does next to slow legislative spending is to emulate his predecessor, the governor. Jerry Brown. He vetoes many spending bills that lawmakers pass after the budget is passed.

It’s in the legislature’s DNA to try to squeeze more dollars out of state coffers after a spending plan has already been drawn up for the year.

They always ask for more, Brown once said. There is no natural border. There is no predator for this type of budget activity except the governor.

In any case, lawmakers, Democrats, counter that it is their constitutional right to keep dipping into the pot.

Many of my colleagues have important issues they are trying to address on behalf of their constituents and they have costs, Rep. Evan Low (D-Campbell) told me. Just as the governor has the right to veto bills, the legislature has the right to send bills to him as part of our democratic process.

But Newsom’s warning to lawmakers he has implanted in veto messages on dozens of spending bills he recently rejected is that if they want to tap into the state’s vault, they better follow a protocol. They must seek approval through the annual budget process, which should end on June 30.

Otherwise, spending money will get out of hand.

This was Newsom’s standard reading that he put into issuing vetoes:

We passed a budget that closed a deficit of more than $30 billion through balanced solutions that avoided major cuts to the program…

This year, however, outside of this budget process, the Legislature sent me bills that, if all passed, would add nearly $19 billion in unaccounted costs to the budget…

As our state faces continued economic risks and revenue uncertainty, it is important to remain disciplined.

It was a powerful message. But a little humor every now and then wouldn’t have hurt. Previous governors occasionally showed some humor in their signing of bills or veto messages.

In drafting a bill to legalize the stuffing and display of dead mountain lions, Brown wrote: This supposedly important bill received overwhelming support from both Republicans and Democrats. If only that same energetic, bipartisan spirit could be applied to creating clean energy jobs and ending tax codes that send jobs abroad.

Gov. Arnold Schwarzenegger used a vulgar acrostic to veto a bill from a representative who had heckled the Republican governor when he botched a Democratic fundraising campaign. The second line of the message began with the letter F and lines six through eight began with the letters y, o, and u.

Gov. Pete Wilson relished vetoing a bill calling for a state study into the best way to dispose of discarded fluorescent light bulbs. Question: How many new bills are needed to study the elimination of incandescent light bulbs? Wilson wrote. Answer: One less than you think.

Newsom recently signed 890 bills and vetoed 156, a mediocre veto rate of 15%.

In 2008, Schwarzenegger vetoed a record 35% of bills sent to him by lawmakers, calling it collateral damage for being 85 days late in passing a budget. That was when budgets required a two-thirds majority of legislative votes. In 2011 it was reduced to a simple majority.

That year, austere Brown vetoed the entire budget. He complained that it would add billions of dollars in new debt to already red ink spending. It is the only time an entire spending plan has been vetoed.

Despite Newsom’s tough veto message and his limitations on when spending can be approved, he’s certainly no pushover.

In his less than five years as governor, state spending has increased 53%, more than $100 billion, from the $203 billion budget Brown left him to $311 billion today.

The governor’s office would not provide the total spending amount that Newsom vetoed. His standard language was used in 64 vetoes.

His spokespeople also did not want to comment on the governor’s veto messages. What is it about saving money? Or was that just a cover for blocking policies he hated?

Nearly every bill on the governor’s desk comes with a cost, said Assembly Budget Committee Chairman Philip Ting (D-San Francisco). Usually the governor has a reason other than spending money [for a veto]. Sometimes he gives the budget excuse.

An example: he vetoed a bill that would require high schools to provide free condoms to students. Was that just because of the unfunded mandate he cited? Or does the father of four also question the policy?

Another: He vetoed a measure that would have provided unemployment benefits to striking union members. He said the unemployment fund was already $20 billion in debt. But did he also think it was crazy to subsidize strikers who voluntarily leave their jobs?

He vetoed many expenditures that amounted to spending money. And he was right.

Once there is an agreed-upon budget, lawmakers should not push taxpayers for more money except in a dire emergency.