Image copyright AP Image caption Trump had just married Melania when the recording was made in 2005

A couple of weeks ago, after the row over Trump "fat-shaming" Alicia Machado, I suggested the Republican candidate lay off our weight.

Warning: This article contains some graphic language

Now, and I can hardly believe I'm having to write this, I suggest he lay off our vaginas.

The day after a video tape emerged in which he suggested he could have any woman he wants because he's a star and so could just "grab them by the pussy", Mr Trump is in a whole ocean of hot political water.

Enough, quite possibly, to sink any chance he had of winning the White House.

Why this tape - and not the myriad other controversies that have dogged him in recent weeks?

First, analyse what he actually says. There is something particularly sexist, I'd say abusive, about this recording.

Read this excerpt:

"When you're a star, they let you do it. You can do anything."

"Whatever you want," the interviewer says.

"Grab 'em by the pussy, you can do anything," Trump replies."

It's the way Mr Trump reveals that he sees women as a piece of sexual meat, something he wants, grabs, discards that is so damning.

Surveys (US government and UN) suggest one in five American women are the victim of rape or attempted rape and a staggering 83% of girls suffer sexual harassment at school.

Mr Trump is not guilty of either of those but his language is exactly the kind of language that encourages men and boys to feel it's okay to abuse women.

There is a violence in the phrases "grab 'em by the pussy" and "you can do anything" that any victim of abuse would recognise and that most women would find sickening.

To dismiss the tape as mere "locker room banter" and imply that the people who are offended are making an unnecessary fuss, or to say, as he did in his bizarre overnight apology tape, that this is just a distraction, compounds his problem.

Image copyright European photopress agency Image caption Trump has offended many groups of people before

But this tape doesn't just offend women, judging from the reaction in the Republican party - it has offended a lot of men too. Whether those men will now withdraw their endorsements of him is yet to be seen.

Mr Trump has denigrated people before. His comments about Muslims and Mexicans have arguably been equally grotesque and many, including some Republicans, have suggested they disqualified him for the presidency too.

Not everyone in America, however, knows a Muslim or a Mexican. Most people, and most voters, do have wives, mothers, sisters or daughters and that's why this tape touches a nerve, with both sexes, in a way his previous remarks haven't.

Powerful men using their position to get sex is nothing new, even in the White House. JFK and Bill Clinton paved that path.

Today some of Trump's supporters are making the case that anyone who voted for Bill Clinton has no right to be offended by Donald Trump.

Image copyright AP Image caption Will the subject of Bill Clinton's infidelities now come up at Sunday's debate?

I've been critical of Mr Clinton's treatment of women, and of Mrs Clinton's role in shielding him, but those supporters are missing the point.

In 2016, don't we all want more from our leaders than another man who feels getting sex from whoever they want, whenever they want is simply one of the perks of power? For my two daughters, I know I do.

How Mr Trump manages the fallout from this isn't clear. He doesn't like apologising. Indeed, he has bragged about never doing so.

Yet overnight he did release a video statement in which he said: "I said it, I was wrong, and I apologise."

In the tape he then goes on to attack both Clintons' records. So on Sunday night, when he debates with Hillary Clinton for the second time, will he raise the issue of Bill Clinton's affairs and Hillary's role in discrediting the women involved, or will he keep quiet about sex altogether?

In the past Mr Trump has not been able to resist lashing out when he's under attack. So, whatever his advisers may caution, I suspect we will see more of that in St Louis on Sunday night.