New Jersey Governor Chris Christie's top economist Charles Steindel will step down at the end of August, reports Elise Young of Bloomberg News. The news comes as New Jersey is in a deepening fiscal hole, with tax revenues falling far short of expectations, and Christie cutting back on scheduled payments into the pension system.

His revenue estimates were off by $3.5 billion

Steindel was responsible for the administration's estimates of how much revenue would be collected each year. But in four of the five years he served in the administration, his forecasts were overoptimistic. Cumulatively, he overestimated how much revenue would come in by $3.5 billion.

A spokesman for New Jersey's Treasury Department told Bloomberg that Steindel decided to leave several months ago. State senator Paul Sarlo, Democratic chairman of the budget committee, told the Star-Ledger that Steindel "had a very rocky tenure." He added, "The big question always will be on these revenue projections: Were these his projections or was he browbeat a little bit?"

Bond ratings for New Jersey have now been downgraded six times.

Economic forecasting is hard, and there isn't malfeasance behind every missed projection. But when the legislature's top budget wonk publicly criticized the estimates as overly optimistic, Christie responded by insulting him and suggesting that he be fired. Based on Steindel's revenue estimates, Christie then proposed an enormous tax cut in 2012 — one it's now obvious the state couldn't afford.

This spring, it became clear that Steindel's estimates were far off yet again, and that New Jersey would face an $800 million budget shortfall in 2014. In May, Christie spoke about how he reacted to this news: "They said, 'We just missed it.' The great thing about an economist is, that's all they have to say. They just look at me and go, 'Oh, governor, I'm sorry. We missed it.' I'm like, 'Yeah, I'm sure you are, but you know, I'm the one who has to fix your mess.'" Bond ratings for New Jersey have now been downgraded six times.

There could be a political silver lining for Christie in New Jersey's budget mess. His office has shown some enthusiasm for another fight with the Democratic legislature over pension cuts. For a sense of his aides' thinking, check out this trailer they posted last week for Christie's forthcoming pension reform proposal:

"Tough choices." "New resolve." That's the image Christie would undoubtedly want to project in a GOP presidential primary. But even this rebranding effort faced some difficulty — the trailer initially included clips of Dwayne "The Rock" Johnson, but they were removed after Johnson's lawyers complained.