WASHINGTON (MarketWatch) — The tumultuous political situation on both sides of the Atlantic makes it tempting to tweak Mark Twain’s bon mot about how many kinds of lies there are to “lies, damn lies and polls.”

Last-minute polls in Britain, for instance, proved to be badly misleading in giving the “Remain” campaign a clear edge in the referendum on leaving the European Union. Even more mistaken were the generally reliable betting odds, which gave the Remain camp an 80% chance of winning just before the vote June 23.

Similarly, in the U.S., we have watched polls roller coaster along, showing presumptive Republican nominee Donald Trump up one day, and presumptive Democratic nominee Hillary Clinton up the next.

“ The only sure thing about this year’s politics is that they are unpredictable. No one saw Trump’s primary victory coming. No one saw Bernie Sanders’ formidable challenge to Clinton’s bid coming, either. ”

Clinton has definitely gotten a bump in recent weeks from effectively clinching the nomination, even as Trump has shot himself in the foot more often than usual.

Dueling polls in the past week have given Clinton as much as a 12-point advantage in the race for the White House, while another put her advantage at only two points, a dead heat given the statistical margin of error, and a third gave Trump a four-point advantage.

Real Clear Politics puts the average of recent polls just under a five-point advantage for Clinton, at least for the moment. Clinton’s average advantage improves slightly in polls that include two third-party candidates, Gary Johnson for the Libertarians and Jill Stein for the Greens.

So what? After all, the national polls can be misleading in determining how the Electoral College vote — the only one that really counts — is going to fall out.

The very illustrative maps at the 270towin website mostly give Clinton an advantage based on polling and forecasting, but not the 270 votes needed to secure victory.

A map based on existing state polls, for instance, has 162 Electoral College votes for Clinton or leaning toward her, compared with 85 for Trump, but a whopping 194 labeled as toss-ups — states with polls but with a difference averaging five points or less. A further 94 votes are in states with no polls.

A toss-up map filling in the gray areas based on historical voting patterns and narrowing the toss-up difference makes 217 votes Democratic and 191 Republican, leaving 130 as toss-ups.

Some forecasters are more definitive. University of Virginia forecaster Larry Sabato has most of the toss-up states leaning toward Clinton, giving her an Electoral College victory with 347 votes to 191 for Trump.

It’s anything but certain, however, that Clinton will end up carrying all the swing states — Pennsylvania, Ohio, Virginia, North Carolina and Florida, among others — that Sabato predicts.

In fact, the only sure thing about this year’s politics is that they are unpredictable. No one saw Trump’s primary victory coming. No one saw Bernie Sanders’ formidable challenge to Clinton’s bid coming, either.

Just as pundits questioned why Clinton had so much trouble fending off a 74-year-old democratic socialist who wasn’t even a member of the party, they can now question why her lead over a patently unqualified contender isn’t much wider.

Given the invective against Trump not only from Clinton and her surrogates but also from her media sycophants, you’d expect the gap to be much larger — if people believed half of what they were hearing.

Nate Silver, the pollster who so correctly called Barack Obama’s victories, has now decided that Clinton has an 80% chance of winning the general election in November.

Silver has departed from his purist polling approach to doll up his predictions with a polls-plus model, but there’s not enough of a track record to determine how reliable this method is. For all we know at this point, his 80% odds for Clinton are as accurate as the British bookies’ 80% odds for the Remain vote in Brexit. Silver was one of the first to acknowledge that he got Trump’s eventual success in the Republican primaries terribly wrong.

“Trump is one of the most astonishing stories in American political history,” Silver said after the real-estate developer clinched the nomination.

The pollster confessed that he acted too much like a pundit and based his early forecasts on educated guesses rather than statistical models, getting them off on the wrong foot.

In the real world, there’s any number of disclosures, revelations, gaffes, legal actions or crises that can alter the picture between now and November.

Now that the primaries are over, the polls are all we have to go by. The two nominating conventions and the three presidential debates could shift polls one way or the other.

But in this volatile political climate, something could happen any day to tilt the fragile support of two unpopular candidates in one direction or another, and keep us guessing.