Thanks to an administration in Washington committed to cutting federal funding for local government and a Congress plagued by gridlock, city leaders often face difficult choices without reliable outside support. And lacking the ability to levy an income tax, cities are then forced to rely on regressive property taxes for essential work.

So late last month when President Donald Trump announced that he would hold a campaign rally in Minneapolis, where I'm the mayor, I had two questions about resources. First, how much extra work would city employees need to do? Second, how could the city secure reimbursement for those excess costs on behalf of the city's taxpayers?

The venue the campaign chose, Target Center, is publicly owned but privately operated. Under the terms of the city's contract with the operator, Minneapolis is entitled to reimbursement for certain costs. In our view, those include excess costs for public safety and traffic control, among other services. Had the venue been privately owned, we wouldn't have had as much leverage to recoup costs.

As mayor, I have a responsibility to protect free speech, even from a president whose rhetoric and policies I find reprehensible. However, it is not my responsibility to subsidize it.

Using the same methodology that city staff relied on to calculate costs for other recent, large-scale events in Minneapolis such as the Super Bowl ($6 million) and the NCAA Men's Final Four ($1.5 million), the projected bill for Trump's campaign stop came out to $530,000.

It's no secret that the president's rallies pose real security concerns, and this event coincided with rush hour. Both factors contributed to that figure, which was higher than might have been incurred for an event with fewer security worries at a time of day without so much traffic. We informed the booking agent of the expected cost and requested payment.

Many things in this president's life have been fluid.

He was once a pro-choice Democrat. He was for the Iraq War before he was against it. He famously disdained presidential golf outings, but now he can't live without them.

One constant in Trump's public and private careers? He doesn't like paying his bills. Just ask the cities of El Paso, Texas, or Tucson, Arizona, or Lebanon, Ohio, all of which are still waiting for the president to pick up his tab for costs their cities incurred hosting his campaign events. Just as some of the cities are large and some are small, so are the expenses and the unpaid bills - $570,000 from El Paso, $16,200 from Lebanon.

In Minneapolis, we need to ensure that our limited funds are put to good uses. Every opportunity we have to save taxpayer dollars and dedicate them to important matters such as affordable housing policy is an opportunity we must seize.

When the president learned that Minneapolis was seeking reimbursement, he did not call me directly to discuss details. He did not seek to better understand the terms of the contract. He took to Twitter to make threats, inflame his base ahead of the event and lash out at me and the diverse city I represent.

Having seen the strain his rallies have placed on other municipalities, I decided to stand up for Minneapolis taxpayers. That meant pushing Trump to do something that is both fundamental to society and antithetical to the way he operates: pay what he owes.

At this point, the matter remains a stand-off: The booking agent is still seeking payment from the Trump campaign, and our position continues to be that the city should be reimbursed.

If this episode holds lessons for other local officials, here they are. When the president brings his show to your town, there may well be avenues available to hold his campaign accountable for the costs it imposes. And if expecting your city to be reimbursed provokes Trump's trademark abuse, it's best to meet his incivility with civility and a bit of humor.

I mentioned earlier that Congress is marked by gridlock, and that it's hamstringing cities' ability to deliver for their residents. That's no great insight. But perhaps one way to break that gridlock and better support cities lies in a simple campaign reform.

Congress should exercise its oversight authority and make clear that public-safety services constitute something of value to a political campaign. Consequently, cities that provide those services for a campaign would be automatically entitled to reimbursement from the campaign instead of being forced to act like a collection agency. As the 2020 campaign ramps up, that's a rule that should have bipartisan buy-in and bipartisan application.

This column was written by Minneapolis Mayor Jacob Frey, for The Washington Post.