Florida Sen. Marco Rubio railed against the relatively obscure issue of eminent domain Thursday, continuing an increasingly heated back-and-forth between himself and Republican front-runner Donald Trump. While eminent domain is necessary for important infrastructure projects, the power is often used to benefit wealthy private developers, Rubio wrote in an op-ed.

It is not the first time that Rubio has mentioned the issue since Trump said that “eminent domain is wonderful” in a segment that aired on Fox News Tuesday. The Florida senator mentioned Trump by name Wednesday when he said that a law he pushed for in Florida's legislature kept developers like Trump from taking property from individuals by force.

"The fundamental right to private property has been under assault for years through our government’s abuses of eminent domain. Eminent domain is the authority vested in government to force the sale of private property,” Rubio wrote Thursday. “While this authority can be a necessary evil in rare cases related to public development, such as the building of crucial infrastructure, its modern use far exceeds this limitation. Today, it is often wielded by crony capitalist politicians to benefit wealthy and powerful private developers. ”

Trump claims to have more credibility when discussing this issue than anyone else in the race because he’s actually had experience forcing property owners from their land and buildings. This is certainly true. For example, he pushed to remove homeowners from property in Atlantic City, where he owns a casino, in the mid-1990s to build a limousine parking lot but was thwarted by three unwilling property owners. He also has lobbied to remove property owners from the land in Bridgeport, Connecticut, where he wanted to build an entertainment complex.

The fight between Rubio and Trump has been heating up since the second Republican debate last month. In the time since, Rubio has been rising in polls, drawing the ire of Trump, who has enjoyed a healthy lead in the race since late July. Rubio is currently in fourth place in averages of national polls from Real Clear Politics, at 9.9 percent. He is the highest polling candidate who has held public office before and is 13.3 points behind Trump.