So Hillary Clinton is opposed to the Trans-Pacific Partnership (TPP), the largest free trade agreement in the history of the universe, is she?

Perhaps we should take that with a grain of salt.

In fact, we might even put those words in quotation marks because they are exactly how her own campaign is said to have described Clinton's last threat to back out of a trade deal: "Take it with a grain of salt."

Or at least that's how the story goes.

Clinton and her team hotly denied it in the 2008 presidential race and instead accused Barack Obama of saying one thing publicly about free trade and another privately.

But those denials never quite explained where the story came from in the first place.

More about that fiasco in a moment, but first let's put Clinton's latest trade talk into its proper context.

As secretary of state, she had intimate knowledge of the TPP negotiations available to her from the very beginning of the talks and for some years afterward.

Based on that, she claimed, approvingly, that the TPP would be an essential part of the Obama administration's foreign policy "tilt" to the Pacific.

She boasted it would be the "gold standard" by which all future trade agreements will be measured.

She and others around her have promoted TPP as not only the biggest and most ambitious open trade zone in the world, but also as a rare foreign policy feather in the cap of the Obama administration.

And now she's decided to trash-talk it and, in the process, double-cross the president she served for four years.

Obama is already out on a limb with Democrats in Congress. They tried to sabotage the president's efforts to bring the trade deal to them for a straight "yes or no" vote earlier this year. That forced him to work with Republicans instead.

So none of this bodes well for the TPP.

But why is Clinton suddenly piling on?

It turns out TPP isn't such a good fit for Clinton at the moment. She's in a Tuesday frame of mind.

Debatable support

Tuesday is the first debate in the race for the Democratic presidential nomination, and many Democrats have been unexpectedly flirting with the most unusual candidate in that race: a 74-year-old, self-described socialist, Senator Bernie Sanders from Vermont.

Sanders is a passionate and articulate opponent of the TPP. So is former Maryland governor Martin O'Malley, who is also running.

Clinton didn't expect such a vigorous challenge and the trade deal is a big part of it.

She could try to adopt a nuanced position on trade, as her husband did in the 1992 campaign when he declared the North America Free Trade Agreement needed "fixing" not "reopening."

But America still isn't sure it wants free trade with Canada, never mind with low-wage countries halfway around the world.

So a nuanced TPP position is trickier for this Clinton. Easier to be against it for now.

Her statement says she is opposing TPP "based on what I know so far."

So she's left herself wiggle room for another flip-flop down the road if and when the coast is clear.

But maybe she's just "talking" in the way politicians sometimes do when the situation calls for something just short of honesty and clarity.

He said she said

Which brings us back to the 2008 fiasco that caused a minor diplomatic incident between the government of Canada and the two Democrats running for president at the time.

Clinton was desperate to match Obama's appeal to Ohio primary voters who felt NAFTA had been a bad deal for their state.

"I will opt out of NAFTA unless we renegotiate it!" she said during a debate.

That was a fairly unequivocal promise and so naturally it caught the attention of the other NAFTA partners, Canada and Mexico. There were concerns.

Those concerns became a matter of intrigue when reporters in Ottawa found an unexpected opportunity to probe the prime minister's chief of staff about them.

The normally taciturn Ian Brodie had wandered into a conversation about the U.S election, and when the reporters asked about Clinton's threat to opt out of NAFTA, he casually blurted out this: "Someone from Clinton's campaign is telling us to take it with a grain of salt. That someone called us and told us not to worry."

Brodie later claimed not to remember the conversation.

The initial reporting was confused about whether it was the Obama's campaign or Clinton's or both apparently saying one thing publicly to America and another thing privately to the government of Canada, but the story landed with a loud thud in both countries.

The result was diplomatically awkward. There was some back and forth on the campaign trail between the two Democratic teams and denials from everyone said to be involved from Washington to Ottawa. An investigation exonerated everyone on the Canadian side.

Clinton's comments this week have surely been noticed from Lima to Hanoi to Canberra. The other partners in TPP would probably like some reassurance that they'll eventually get what they bargained for in the deal.

Maybe they're expecting a private reassurance.

Who knows, maybe they'll get one?

But what would that be worth these days?

American politics is in a strange way at the moment. Exotic candidates are buffeting the establishments of both parties.

Sanders is not the only one enjoying his moment.

We haven't even mentioned Donald Trump's views on trade deals.