The 2016 Republican presidential primary had already become bitter.
Donald Trump had insulted his opponents, given them mocking nicknames and turned personal attacks into a regular feature of the campaign.
But in March 2016, the fight between Trump and Texas Senator Ted Cruz crossed another line.
Their wives became targets.
And it started with an advertisement Ted Cruz's campaign hadn't even produced.
The Melania Trump Ad
The controversy erupted ahead of the March 22 Republican caucuses in Utah.
An anti-Trump super PAC called Make America Awesome created a Facebook advertisement aimed at Utah voters.
The ad used a provocative photograph of Trump's wife, Melania Trump, from a 2000 British GQ modeling shoot.
It was an obvious attempt to damage Trump among socially conservative voters.
But there was an important distinction:
Ted Cruz's campaign had not created the ad.
Federal law prohibited the super PAC from coordinating its advertising with Cruz's campaign, and Cruz denied having anything to do with it.
Trump nevertheless blamed Cruz.
“I Will Spill the Beans on Your Wife”
On March 23, Trump responded publicly.
He accused Cruz of using the photograph of Melania and issued a warning:
“Be careful, Lyin' Ted, or I will spill the beans on your wife!”
Trump didn't explain what “spill the beans” meant.
That ambiguity immediately raised another question:
What exactly was Trump threatening to reveal about Heidi Cruz?
Cruz responded that the Melania advertisement hadn't come from his campaign.
He then warned Trump to leave his wife out of the fight.
But the dispute wasn't over.
It was about to become even more personal.
Trump Posts the Photograph
The following night, Trump retweeted an image originally posted by one of his supporters.
It placed photographs of Melania Trump and Heidi Cruz next to each other.
Melania was shown in a polished professional photograph.
Heidi was shown in a considerably less flattering image.
The message was obvious enough that it didn't require an explanation.
The graphic declared that the photographs were worth “a thousand words.”
Trump had taken a campaign dispute involving an outside political advertisement and responded by publicly circulating an image ridiculing the physical appearance of his opponent's wife.
Cruz responded almost immediately.
“Donald, real men don't attack women. Your wife is lovely, and Heidi is the love of my life.”
Cruz Explodes
By the following day, Cruz was furious.
Speaking to reporters while campaigning in Wisconsin, he abandoned the restrained language politicians normally used when discussing their opponents.
“Donald, you're a sniveling coward. Leave Heidi the hell alone.”
Cruz said spouses and children should be considered off-limits in presidential campaigns.
He accused Trump of bullying his wife and described the attack as the behavior of a “small and petty man.”
This was no longer a disagreement over immigration, taxes or foreign policy.
Two leading candidates for the Republican presidential nomination were publicly fighting over their wives.
Heidi Cruz Responds
Heidi Cruz also addressed Trump's comments.
She told reporters she wasn't particularly concerned about Trump's threat.
She continued campaigning for her husband while the controversy dominated political coverage.
But her involvement highlighted something unusual about the episode.
Heidi Cruz wasn't running for president.
Neither was Melania Trump.
Yet both women had been pulled directly into an increasingly hostile fight between their husbands.
Trump Defends His Response
Trump and his campaign maintained that the attack on Heidi Cruz had been a response to the advertisement involving Melania.
From Trump's perspective, his wife had been attacked first.
His campaign argued that he was responding to an inappropriate political attack against his family.
There was still a fundamental problem with that defense:
Cruz hadn't produced the advertisement.
The group responsible was an independent anti-Trump super PAC.
Trump had blamed Cruz anyway.
FactCheck.org subsequently examined Trump's allegation that the Cruz campaign was responsible and found that Trump had provided no evidence supporting it.
From Political Rivalry to Personal Feud
The Trump-Cruz relationship had deteriorated dramatically during the Republican primary.
Months earlier, Cruz had largely avoided attacking Trump.
That strategy disappeared as Trump became the frontrunner and Cruz emerged as one of the few remaining candidates capable of challenging him for delegates.
Trump began calling him “Lyin' Ted.”
Cruz increasingly questioned Trump's temperament and conservative credentials.
By late March, their rivalry had moved beyond political disagreements.
Now their spouses were involved.
A Different Kind of Presidential Campaign
Presidential campaigns have always included personal attacks.
But Trump's willingness to use social media allowed those attacks to reach millions of people almost instantly.
There was no carefully prepared campaign advertisement.
No lengthy speech.
No policy argument.
A photograph could be posted or retweeted in seconds and immediately become national political news.
That was exactly what happened with Heidi Cruz.
A super PAC published an advertisement involving Melania Trump.
Trump blamed Ted Cruz.
Trump threatened Cruz's wife.
Cruz warned Trump to leave her alone.
Trump then circulated the photograph anyway.
And within hours, one of the most important political stories in America wasn't about what Trump or Cruz planned to do as president.
It was about their wives.
The Campaign Was Getting More Personal
The Heidi Cruz episode ultimately had little to do with the issues Republican voters were supposed to be deciding.
But it revealed something about the increasingly personal nature of the 2016 campaign.
Trump had already demonstrated that he was willing to attack opponents in ways previous presidential candidates often avoided.
Now that approach had expanded beyond the candidates themselves.
The families were no longer necessarily off-limits.
And as the Republican primary moved toward its final months, the contest between Donald Trump and Ted Cruz was no longer simply a political rivalry.
It had become personal.