"I, like many New Jersey residents, was shocked to see how much the governor's out-of-state political travel has cost taxpayers," Singleton said in an email about the bill.
"Given that these expenses are clearly not related to state business and growing, the question of whether taxpayers should be responsible to foot the bill I believe is a valid one," he said. "The proposal would create a transparent and open process that would entrust our various ethics committees with determining whether the expenses are related to official state business. If they’re not, the official would be required — rightfully so, in my opinion — to reimburse the state."
Christie spent much of 2015 outside of New Jersey campaigning for the presidency. He was also frequently outside the state in 2014, when he was serving as chairman of the Republican Governors Association.
More recently, Christie has traveled to endorse and campaign for billionaire Donald Trump, who is the front-runner to win the GOP's presidential nomination.
Christie's personal travel expenses were covered by his own campaign or, more recently, by Trump's. However, expenses related to his protective detail are borne by taxpayers.
Singleton's bill, which is co-sponsored by Assemblyman Vincent Mazzeo, D-2nd of Northfield, would leave it to the State Ethics Commission or Joint Legislative Committee on Ethical Standards to decide if Christie's security detail and other travel expenses should be covered by taxpayers.
The bill would require the governor, members of the Legislature and other state officials and employees to submit a written report every July to either the commission or committee detailing any expenditures from the previous fiscal year from allowances for state receptions, operations of official residences, transportation, protection and security, or other similar expenses.
The reports would be required to include receipts for purchases and services, as well as a brief description of the item or service.
The commission or committee would be charged with reviewing the reports and determining if any of the expenses were not incurred as the result of "official state business."
Any expenses found to fall outside of state business would need to be reimbursed by the official or employee, with interest equal to the rate of inflation.
A spokesman for the Governor's Office did not immediately respond to a request for comment. Typically, the office does not comment on legislation until Christie signs or vetoes it.
Christie previously said the expense of the state police security detail is outside his control.
"The taxpayers probably don't want to pay for the state police to go with me to the supermarket, either. But that's not my choice," he said earlier this month during a Statehouse news conference. "The state police believe that the appropriate thing to do to protect me and my family is for them to be with me at all times. And they are with me at all times."
Singleton and Mazzeo introduced similar legislation during the previous legislative session that required the reports solely from the Governor's Office. The bill never advanced from the Assembly Budget Committee, and they chose to rewrite it so that it applied to state lawmakers and other employees besides the governor.
Although the bill leaves it to the commission or committee to decide whether Christie's security at political events is state business, Singleton said his own opinion is that the governor should reimburse the state for that expense.
"I think that while the state police is required to protect the governor, using public resources to protect him at political events perverts that obligation," he said. "The governor should recognize that and reimburse the state, as other governors did in a similar position, for that time instead of simply nonchalantly dismissing it."