Sen. Ted Cruz (third from right) leaves a rally in Myrtle Beach, S.C., on Wednesday. (Reuters/Randall Hill)

This post has been updated 

In the final days of his New Hampshire campaign, Sen. Ted Cruz (R-Tex.) never mentioned the man who was likely to beat him. He would discuss the evils of eminent domain, but not mention the mogul who actually used it. He would warn voters not to vote for false or squishy Republicans, but did not name any. At the final debate before the primary, and at least one town hall, he only hinted at Donald Trump by mentioning the need for a wall on the U.S.-Mexico border, and adding: "I've got an idea of who should build it."

When the primary was over, Cruz headed south. The fleece, and the gloves, came right off.

“The other candidates are not able to beat Donald Trump,” Cruz told conservative radio host Mike Gallagher on Wednesday morning. “You can’t beat Donald coming from the left. It doesn’t work. If you campaign against Donald saying, ‘Hey, I’m more liberal than you, I’m more into amnesty than you, I’m gonna be softer on radical Islamic terrorists than you,' it doesn’t work, as we’ve seen twice.”

Cruz's on-again, off-again battle with Trump is on again, and the senator and his allies intend to bring the front-runner down with the arguments that worked in Iowa. Trump's attempted seizures of private property, the 1999 admission that he was "very pro-choice," and his confusing argument in favor of "single payer" health care -- all of it was fair game again.

"We’ll continue to show that Donald Trump is not a conservative, he is not even the populist he portrays himself to be, but he’s the establishment," a Cruz aide told The Washington Post. "He’s always been in and around the establishment. He’s played that whole game and he will go to Washington and cut deals, and that’s the last thing people want.”

The official campaign effort was starting slowly. Its post-primary salvo began with a 45-second Web ad, "Playing Trump," in which children unsubtly use a Donald Trump action figure to bash in a dollhouse, yelling "eminent domain!"

That ad was not appearing on television. Keep the Promise I, the most active in the trio of pro-Cruz super PACs, was getting a more aggressive start. According to strategist Kellyanne Conway, the PAC had already bought around $2.5 million of ad time in South Carolina, and around a fifth of that in Nevada, for ads that promoted Cruz and attacked both Trump and Sen. Marco Rubio (R-Fla.). The anti-Trump spot, "Trumpcare," linked his amorphous support for universal health coverage with Hillary Clinton's campaigns for the same.

"There’s some nagging concern he’s gone through the political witness protection program to emerge a spanking new conservative," Conway explained, suggesting that what worked in Iowa would work in the South. "The greatest problem we’ve seen is a lack of specificity and an unwillingness to go deep into policy. And eminent domain is a big problem for him. If Trump’s entire narrative of 'I’m for the little guy' hits a speed bump, it’s because South Carolina becomes more familiar with the victims of Trump’s success."

The Cruz campaign sent a fundraising email Wednesday afternoon declaring that the results in Iowa and New Hampshire show Cruz and Trump are in a two-man race. "Friend, let me be blunt. I can beat Hillary Clinton. Donald can't," the email read. It stated that Trump is so rattled by Cruz's "surge in the polls" and Iowa win "that he has decided to continue his scorched earth campaign in an attempt to burn down everyone and everything in his path." It said that Trump supports "Hillary-style healthcare" and partial birth abortion.

In 2012, a similar strategy proved remarkably damaging to front-runner and former Massachusetts governor Mitt Romney. A pro-Newt Gingrich PAC, Winning the Future, launched a mini-documentary and ad campaign that attacked Romney's work at Bain Capital, interviewing workers who'd lost their jobs in turnarounds. Keep the Promise had not interviewed Vera Coking, the elderly Atlantic City woman who fought (successfully) to keep a home against Trump's attempt to seize it as part of a casino expansion. But it had not ruled it out.

Other Cruz endorsers had their own ideas for exploiting Trump's weaknesses. State Rep. Wendy Nanney, a legislator and leader of Cruz's state pro-life coalition, suggested that the Republican front-runner had not been exposed on his old abortion views.

"Voters here have not been doing a lot of investigating yet," she said. "A lot of voters have not looked into Trump’s past, but we're going to get out the message that Senator Cruz has always stood for life."

State Sen. Lee Bright, another early Cruz supporter, suggested that Trump was vulnerable on the "single payer health care" quotes. But neither he nor Nanney echoed the tone of Cruz, who has called the mogul-turned-candidate an obvious phony.

"He's against the establishment, but Senator Cruz actually had a record of fighting and beating the establishment," Bright suggested.

The infrequent polls of South Carolina have provided little clarity about the current strength of either candidate. In an average calculated by RealClearPolitics, Trump leads the field with 36 percent support, with Cruz at 20 percent, more definitively in second place. But all of the polls were conducted before the Iowa caucuses and before Trump's New Hampshire comeback.

Dan Tripp, the South Carolina state director of Keep the Promise, was unsure why the battle with Trump seemed to start and stop during the last week.

“Maybe we’re just trying to let the bully learn the lesson and leave us alone," Tripp said. "We’re trying to show some mercy to the bully." South Carolina, he suggested, was "where we have a chance to go mano a mano with Trump and, you know, like we did in Iowa, show that a real ground game can make the difference."