(CNN) Ted Cruz will launch his most forceful attack yet against Donald Trump in a TV ad that accuses Trump of buying political influence "in a pattern of sleaze stretching back decades."

"Vera Coking's home was all she had left but it stood in Donald Trump's way and the limousine parking lot he wanted for his casino," the narrator says. "To him, she was a nobody."

The ad flashes to an October 16 Washington Post article about Trump's ties to the mob in Atlantic City, and slams the real estate mogul for having "bankrolled politicians to steamroll the little guy -- a pattern of sleaze stretching back decades."

It also shows footage of Coking saying about Trump, "Heart? He doesn't have no heart, that man."

The ad closes with this ominous warning: "Trump uses power for personal gain. Imagine the damage he could do as president."

CNN has reached out to Trump's campaign for comment.

It comes just as the Trump campaign decided to pull an anti-Cruz ad and replace it with a positive spot in South Carolina.

Trump's campaign manager Corey Lewandowski said the campaign was focused on running a " positive campaign ," though he did not rule out putting up attack ads again before the South Carolina primary.

Cruz's ad is the latest in a flurry of recent political attacks that Trump and Cruz have levied at one another as they've battled in the early states.

After Cruz won Iowa and Trump came in first place in New Hampshire this week, both candidates are now hoping to notch their second victory in the South Carolina GOP primary on February 20. Based on limited polling from the southern state, Trump so far has a sizable lead there.

With the airwaves cluttered with ads from multiple candidates on more traditional political issues like taxes and immigration, Cruz allies also hope that hits on eminent domain will be memorable.

Many conservatives believe eminent domain — a practice in which the government seizes private property — amounts to government overreach. But Trump has remained consistently supportive of the practice.

"Ted Cruz complains about my views on eminent domain, but without it we wouldn't have roads, highways, airports, schools or even pipelines," Trump tweeted last month.

Eminent domain and Coking's story were prominently featured in Cruz's first attack ad against Trump, which claimed the real estate developer "won't change the system — he's what's wrong with it."

But the new ad that's being rolled out this week uses the issue to deliver a hard punch to Trump's character and ethical values, less than ten days out from the South Carolina contest.