Republican political campaigns and U.S. government agencies have spent more than $16 million on Trump properties for events, lodging, meals, rounds of golf and more since Donald Trump launched his presidential campaign in 2015, according to data collected by ProPublica.

Expand chart Data: ProPublica; Note: Chart does not include five undated payments and three payments of negative amounts; Chart: Harry Stevens/Axios

Why it matters: Government ethics watchdogs have claimed that this kind of spending reveals a presidential conflict of interest — or at the very least, bad optics. In May, a federal judge allowed a lawsuit accusing Trump of breaking the Constitution's Emoluments Clause, which bans improper payments from individual states and foreign governments, to move forward. A final ruling is expected in July.

The big picture:

84% of the more than $16 million spent on Trump properties since 2015 came from Trump's own campaign, most of which went to chartered planes from Trump-owned TAG Air.

spent on Trump properties since 2015 came from Trump's own campaign, most of which went to chartered planes from Trump-owned TAG Air. The largest single payment was $1,271,944, paid by Trump's campaign to his chartered jet company, on November 28, 2016, 20 days after Trump's election.

paid by Trump's campaign to his chartered jet company, on November 28, 2016, 20 days after Trump's election. Trump's campaign spent another $473,662 on that same date at five other Trump properties — rent at Trump Tower in New York, food at Trump Restaurants in New York and Trump Golf Club in Virginia, and lodging at Trump Hotel Las Vegas and Trump Hotel D.C.

on that same date at five other Trump properties — rent at Trump Tower in New York, food at Trump Restaurants in New York and Trump Golf Club in Virginia, and lodging at Trump Hotel Las Vegas and Trump Hotel D.C. The largest payment made by taxpayers came from the Department of Homeland Security, which paid $56,330.48 for an event at Trump Golf Club Miami on May 31, 2017.

came from the Department of Homeland Security, which paid $56,330.48 for an event at Trump Golf Club Miami on May 31, 2017. When Trump has traveled as president , a third of the time he has stayed at his own properties, according to ProPublica.

, a third of the time he has stayed at his own properties, according to ProPublica. Trump's properties, especially the International Hotel off of Pennsylvania Ave. in D.C., have also attracted foreign government officials from Saudi Arabia, Kuwait, and Malaysia as well as pro-Turkish groups, according to watchdog group Public Citizen.

especially the International Hotel off of Pennsylvania Ave. in D.C., have also attracted foreign government officials from Saudi Arabia, Kuwait, and Malaysia as well as pro-Turkish groups, according to watchdog group Public Citizen. Trump promised to donate any profit from foreign governments to the U.S. Treasury. In March, the Trump Organization claimed that they had done so for their 2017 profits by donating around $150,000, according to the Wall Street Journal.

from foreign governments to the U.S. Treasury. In March, the Trump Organization claimed that they had done so for their 2017 profits by donating around $150,000, according to the Wall Street Journal. The joining fee for the Mar-a-Lago beach resort were doubled to $200,000 following Trump's election and just before his inauguration, members also pay an additional $4k a year in annual dues.

were doubled to $200,000 following Trump's election and just before his inauguration, members also pay an additional $4k a year in annual dues. The D.C. Trump hotel managed to make more money than expected at the beginning of 2017 —$18 million in the first four months — due to raising room rates and charging extravagantly for food and drink.

managed to make more money than expected at the beginning of 2017 —$18 million in the first four months — due to raising room rates and charging extravagantly for food and drink. Ivanka Trump has also benefitted greatly from Trump properties, raking in $3.9 million from the Trump International Hotel in 2017.

Be smart: ProPublica included a caveat that "federal taxpayer data is incomplete because agencies are fighting disclosure. We will add more as it comes in."

The bottom line: Even if no rules or laws are being broken, it's clear that Trump's presidency has been uniquely beneficial to his business, which makes some critics and ethics experts uneasy.

Go deeper: The Republicans giving Trump properties the most money