The media are mystified. The partisans are flummoxed. Eight months into Trumpmania, the Donald’s popularity has shown no sign of abating. He just breezed to a 20-point victory in New Hampshire, and he now commands an unambiguous (if very early) lead in the delegate count. So why has no one bothered to mount a sustained attack on the GOP front-runner? As of late January, “literally, zero dollars in super PAC advertising [had] been run against him,” said the Washington Examiner’s David Drucker. The overwhelming majority of the fire from all sides has been directed farther down the polling ranks at Marco Rubio, who has absorbed tens of millions in negative advertising in recent months. The casual observer could be forgiven for thinking the candidates had all gone mad.

Yet however reckless this one-way ceasefire might be in the aggregate, it is brutally rational from the standpoint of the individual campaigns. It’s not that the other Republicans have deemed Trump invincible, that they’re scared of blowback, or that they’re pulling punches. Every campaign has a strategy to deal with Trump. Every apparatus has potent attacks at the ready. Every candidate is itching for his shot. The problem is the way the incentives line up. As Jay Cost has phrased it, the motives have yet to align with the means. Plenty of outside groups have altruistic goals of saving the party and the broader conservative movement from Trumpism, but they have not found the right patrons to finance their efforts. The campaigns, and particularly their allied super PACs, have ample means, but no motive at this juncture.

For all the griping from the pundit class, rival campaigns, and even antsy donors, there’s no scenario whereby peeling votes away from the front-runner would aid Jeb Bush’s exceedingly narrow path to victory. If anything, doing so would clear more space for Ted Cruz to operate. So, short of a spontaneous “act of love,” Jeb’s outside enforcer, Mike Murphy, is not going to wake up tomorrow and launch an all-out assault on Donald Trump.

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To the extent that the Bush campaign has gone after Trump, a fact they’ve not been shy about bringing up, it has been to use him as a foil — an uncouth and erratic contrast to the staid and stately Jeb. The pitch is not to Trump backers, or even Trump-curious undecideds, but rather to the sort of moderate and Establishment-friendly voters who are divided among Bush and his mainstream competitors. Likewise, Marco Rubio’s first swats at Trump have been geared towards making a contrast argument for himself on national-security grounds.

#share#For Cruz’s part, despite his being the presumed beneficiary of a Trump swoon, his attacks have also been muted. His main arguments against Trump have focused on values, ideology, and cronyism, charges that are unlikely to resonate with the Donald’s core supporters. But, like Bush’s jabs, this message plays into the way Cruz has tried to frame the race. It is not so much an appeal to would-be Trump voters as a move to firm up his support among those who are searching for a true conservative.

But as the campaign moves south to the notoriously cut-throat Palmetto State, there are signs that the gauntlet has been thrown. Not only did the Cruz campaign release one of the most entertaining ads of the cycle, using bratty children to convey Trump’s baggage in a clever way, they also took a new and more effective tack in prosecuting their argument on eminent domain. The campaign’s first stab at this issue missed the mark, leading with a simplistic explanation of the legal jargon before making a conservative case against the practice. In doing so, the campaign provided a legal pretext for Trump’s behavior before getting around to the attack. This led to a fair number of process stories and a ho-hum debate exchange parsing the issue, but did little in the way of advancing the storyline. By contrast, his latest spot goes for the jugular, attempting to undermine Trump’s populist appeal using an avenue that I, among others, have long advocated. As I wrote back in January,

The key to this approach is not to explain, but to illustrate. Let the images speak for themselves — make it not about the issues, but about the people. Vera Coking need[s] to be [a] household name.

The Cruz spot does just that, even driving it home by saying that “Trump bankrolled politicians to steamroll the little guy.” This opens a potent line of attack that will pay dividends down the line. (Hint: Just Google “Trump University” or the “Polish Brigade” that built Trump Tower.)

#related#Based on the collective inaction to date, it’s clear that the campaigns aren’t taking the threat of Trump and the prospect of his unstoppable momentum as seriously as the talking heads are. And while he did notably exceed his polling average in New Hampshire, pulling just over a third of the vote in a notoriously idiosyncratic state puts the Donald in the same position as Pat Buchanan in 1996. But timing is everything in politics, and it appears the Cruz campaign has decided it is time. And since Cruz is the only candidate who enjoys a clear overlap with Trump’s anti-establishment constituency, it was always necessary for him and his allies to fire the first shot. With the bromance of a few short months ago in tatters, perhaps the battle will now be joined, and the other candidates will decide that it’s prudent to follow suit.

— Liam Donovan is a former GOP staffer who works in government relations in Washington, D.C. You can follow him on Twitter at @lpdonovan