On Wednesday afternoon, when asked at a news conference in Trenton whether he was “nervous and intimidated” by the prospect of lawsuits from unions who have vowed to sue to force him to make the payments on public employee pensions, Mr. Christie deadpanned: “Two words that are often associated with me, ‘nervous and intimidated.’ Listen, I know that some people think that now’s the time where you can pile on. You know, I make the decisions that I believe are the right thing to do.”

“I didn’t think it would happen this quickly,” the governor added, referring to the hole the pension payments had created in the budget.

But a host of independent reports and the ratings agencies have warned about the problems for years: The governor’s projections for economic growth have been too optimistic, resulting in midyear cuts to the budgets three years in a row. He has not kept enough of a cushion against bad economic news — the state’s surplus is about .9 percent of the total budget, the lowest in a decade, and below the national average of more than 8 percent. Connecticut, for example, was like New Jersey in suffering lower than expected tax revenues this year, but was not forced to adjust the budget because it maintains a bigger rainy day fund.

The ratings agencies have warned that his reliance on “one shots” to fix budget holes — a practice Mr. Christie himself railed against when he ran against Gov. Jon Corzine in 2009 — was making the budget structurally unsound, and that he would have to either raise taxes or cut programs to restore health.

“This has been a multiyear trend that has now reached a very weak position,” said Baye B. Larsen, who wrote the report that accompanied the Moody’s downgrade.

Mr. Christie was widely praised in 2011 when he and Democratic leaders in the Legislature agreed to increase payments on the state’s pension obligations, which had been almost entirely ignored by governors since Christie Whitman. (Mr. Christie told Mr. Schieffer that Mr. Corzine made “zero” payments; in fact, he paid as much or more than Mr. Christie for two years, then reverted to the previous model when the recession hit.)

In return, employees had to contribute more toward their benefits, and won the right to sue if the state reneged on its payments. It made him seem the adult on the national stage, daring, as he said, “to touch the third rail of politics in order to bring reform to an unsustainable system.” This year, the payment was to be $1.6 billion; Mr. Christie said this week he would pay $696 million. In the fiscal year that begins July 1, he was to pay $2.25 billion; he will pay $681 million.