This was a bad week for the Republicans.
In a race which has been nasty, mean-spirited and at times vulgar, new depths have been plumbed.
It all started with a Facebook ad.
Aimed at conservative voters in Utah, the ad pictured a naked Melania Trump from her modelling days sprawled on a fur rug. It carried the legend, "Meet Melania Trump, your next first lady. Or, you could support Ted Cruz on Tuesday".
The ad was paid for the Political Action Committee "Make America Awesome" which has been established by Republicans who are determined to stop Donald Trump securing the party nomination to run for the US presidency.
In the small print in the ad, the following was stated: "Not authorised by any candidate."
That wasn't enough for Trump, who immediately blamed his main rival, Texas senator Cruz, warning him he would "spill the beans" about Cruz's wife Heidi.
Instead, Trump himself tweeted out a glamour shot of his wife next to a less than flattering shot of Mrs. Cruz, with the caption adding: "No need to 'spill the beans'. The images are worth a thousand words".
Cruz went on the offensive, calling Trump a coward. Taking lines from the Aaron Sorkin movie "The American President", he added: "If Donald wants to get into a character fight, he's better sticking with me because Heidi is way out of his league".
Trump has been asked about the spat but repeatedly turns to the line that he didn't start it.
As one observer stated, it's like the candidates forgot this was a battle for the presidency of the United States.
Public spats
Negative campaigning is nothing new.
It's been around in American politics for more than a 150 years - Andrew Jackson won the White House in 1828 but he believed the death of his wife before he took office was down to negative campaigning which tore her reputation to shreds.
But just when it looked as if things would blow over, Cruz spent Friday denying a story in the National Enquirer magazine alleging he had at least five extramarital affairs.
Calling the story "garbage" and a "tabloid smear", he blamed Trump for planting the story - the magazine publisher is an old Trump friend.
In a story full of anonymous quotes, the only person who went on the record is a former Trump advisor.
Trump told anyone who'd listen: "Ted Cruz's problem with the National Enquirer is his and his alone".
Without too much sincerity he added: "While they were right about OJ Simpson, John Edwards and many others, I certainly hope they are not right about Lyin' Ted Cruz".
New lows
This is a nomination contest which has debated the size of candidates' hands and by extension the size of their genitals; where candidates have been attacked as sweaty and low energy; where they have openly called each other liars and been accused of wetting themselves during debates.
Yet through these battles, only Trump has emerged stronger.
Mean tweets, insulting pictures and tabloid stories have dominated the Republican week, a week where there were murderous attacks in Belgium, Iraq and Pakistan; when America's President made a ground-breaking trip to Cuba; and a leading figure in the Islamic State of Iraq and the Levant (ISIL) group was killed.
When comments about the size of the candidates' penises dominated the Republican public debate, many believed this campaign cycle had struck an all-time low.
Yet, this past week suggests there may be still a way to go before we get there.
