If you're just now hearing the unsubstantiated rumor that Ted Cruz engaged in multiple extramarital affairs, there's a good reason: Mainstream media outlets had been ignoring the gossip since Wednesday afternoon, when the National Enquirer posted it online.

But by midday Friday, there was no avoiding the smutty story line — not after a Boston Herald columnist and radio host suggested live on CNN that Cruz's former communications director had slept with her one-time boss, with the former Cruz aide appearing right there with her on live TV.

Republican presidential candidate Ted Cruz is blasting rival Donald Trump for a National Enquirer story accusing Cruz of having five mistresses. Here's a breakdown of how a week of fighting got us here. (Sarah Parnass/The Washington Post)

Shortly thereafter, the Republican presidential candidate felt compelled to tell reporters that the rumors are "garbage" and to post a denial on Facebook.

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CNN anchor Kate Bolduan, who's had an eventful couple days on the air, shook her head in dismay as Adriana Cohen, a Trump enthusiast, hijacked a live interview that also included former Cruz spokeswoman Amanda Carpenter and steered it straight into the gutter. Bolduan asked Cohen if she was ready to move on from another unseemly subject — Trump's tasteless, Wednesday-night retweet that unfavorably compared the physical appearance of Cruz's wife, Heidi, to that of Trump's wife, Melania.

COHEN: Oh, absolutely. We should move on. Where we should move to is the National Enquirer story that has reported that Ted Cruz has allegedly had affairs with five mistresses, including — you've been named, Amanda.

BOLDUAN: I'm sorry. I don't think that's moving on at all, Adriana.

COHEN: No, well I'd like to know, if we're going to call Donald Trump's character into question, I would like Ted Cruz to issue a statement whether or not the National Enquirer story is true, whether he has had affairs with many women, including, uh, you were named, Amanda. Will you denounce this story or will you confirm it?

BOLDUAN: Let me just — let me just step in, really quick. Amanda, I will give you a second. Let me just be very clear. It will come as no surprise to our viewers. CNN has no reporting on what you're talking about from the National Enquirer. Amanda, go ahead.

CARPENTER: What's out there is tabloid trash. If someone wants to comment on it, they can talk to my lawyer. It is categorically false. You should be ashamed for spreading this kind of smut.

Cohen, a media professional, surely knew what she was doing. And she succeeded. A story without any solid reporting behind it, which many news outlets had managed to dismiss for two days, was suddenly out there on a major cable news station. Cohen created a spectacle that she knew others in the press, who had exercised restraint, would have to cover.

This is how Trump-ism works. The disheartening reality for journalists is that the Republican presidential front-runner and his allies are getting frighteningly good at forcing them down roads they have tried to avoid.

Friday's events were case in point.