Republican presidential candidate Sen. Ted Cruz salutes during a campaign stop Wednesday in Hollis, N.H. (AP Photo/Matt Rourke)

Sen. Ted Cruz (R-Tex.) has launched his first attack ad against GOP primary rival Donald Trump, painting the real estate mogul as a corporate crony who will use the power of the government to make himself rich.

The ad, which Cruz released on Twitter, starts with footage of a bulldozer and the words "eminent domain."

"Fancy term for politicians seizing private property to enroll the fat cats who bankroll them. Like Trump," it said, cutting to a clip of Trump saying that eminent domain is "wonderful."

It then tells the story of a widow in Atlantic City, N.J., whom Trump spent years litigating against in an attempt to take her house, which sat near a Trump casino. The ad states that Trump "colluded with Atlantic City insiders" to take the woman's home in order to create a parking lot for one of his casinos.

Read: The time Donald Trump’s empire took on a stubborn widow — and lost

Trump, the ad said, "won't change the system; he's what's wrong with the system."

After months of a detente with Trump, Cruz has gone on the offensive in recent weeks as the Iowa caucuses and New Hampshire primaries approach. In New Hampshire this week he excoriated Trump for supporting eminent domain in a rural, more libertarian-leaning part of the state, hammered on Trump's support for bank bailouts and the government stimulus and for his donations to Democratic politicians including New York Gov. Andrew Cuomo and presidential candidate Hillary Clinton.