Four years ago this week, Mitt Romney spokesperson Eric Fehrnstrom made a memorable remark. He was talking about the pivot candidates make, when they feel confident enough about winning the nomination to start running their general-election campaign.

“You hit a reset button for the fall campaign,” Fehrnstrom said, on CNN. “Everything changes. It’s almost like an Etch-A-Sketch; you can kind of shake it up and restart.”

You’re not supposed to admit it so openly, with such a vivid metaphor—especially when your candidate has a reputation for changing positions for political convenience. But it’s essentially true: candidates run differently in the general election than they do in the primaries.

The trick is figuring out exactly when the nomination is secure enough to make the switch.

Earlier this month, it looked like the frontrunners in both parties were eager to make that pivot—to leave their intra-party tensions behind, and start campaigning against each other.

But that has since changed. Now, Hillary Clinton and Donald Trump are about to find out whether their own Etch-A-Sketch moment is finally here—or is still a long way off.

On Tuesday, both parties hold primaries in five big states: Florida, Illinois, Missouri, North Carolina, and Ohio.

Clinton is expected to win in Florida and North Carolina, continuing her sweep of the Southern states. If she takes the other three states as well, she can start safely acting like the presumptive nominee. 

But Bernie Sanders is fighting hard, especially in Ohio, and is polling close in Illinois. If he wins at least one state, and especially if he wins two, then it’s likely the two campaigns will have to keep grinding out for delegates—much like Clinton and Obama did eight years ago—perhaps as long as the June 7 California primary.

Things could go even longer for the Republicans. If John Kasich and Marco Rubio win their home states of Ohio and Florida—which both award delegates winner-take-all for the GOP—and Ted Cruz does well in the other states, then, many are calculating, it will be very difficult for Trump to reach the majority of delegates needed to claim the nomination.

In other words, the Republicans could be headed to a contested convention in July.

On the other hand, if Trump wins both Florida and Ohio, and picks up delegates in Tuesday’s other contests, he too could start treating the nomination as a fait accompli.

Clinton appeared to have turned the corner on March 1, when she dominated the “Super Tuesday” primaries. She had won 10 states to that point, including big prizes Texas, Virginia, Georgia, and Massachusetts; Bernie Sanders had won just five, mostly small ones.

Thinking that the nomination was nearly inevitable, Clinton’s rhetoric shifted. She didn’t start speaking like a nominee, but she began criticizing Trump more, and Sanders less. She spoke several times of her expectation that, if she did become the nominee, Sanders would support her and help her win the trust of young progressives in his corner.

Even more important, it seemed as though Sanders and his followers might have been on the verge of accepting the decreasing likelihood of victory.

But then Sanders won caucuses in Kansas, Nebraska, and Maine, followed by a stunning victory in Michigan last Tuesday.

While Clinton still holds a significant delegate lead, there suddenly appeared the possibility of Sanders winning other Midwest and Rust Belt states, and dragging the fight out potentially as long as the June 7 California primary.

The renewed sense of possibility has emboldened Sanders to go on a sharper attack on Clinton—“Sanders Has Gotten Nastier,” a Washington Post headline declared this weekend—zeroing in on her trade policies in particular.

Sanders also tweeted (or someone did from his account) an allegation during the county caucuses in Iowa over the weekend, where the February caucus votes are turned into actual delegates to the national convention: “Effort under way right now by @hillaryclinton and party allies to steal Polk County Iowa conv. election Bernie won earlier today.”

That and other clashes have increased divisiveness, just when Clinton was hoping to start uniting the party. Sanders supporters are increasingly threatening to not support Clinton if she is the nominee--even lefty Ben Cohen, of Ben & Jerry’s, seemed to indicate that in an interview.

Of course, that’s nothing compared to the racheted-up divisiveness in the Republican Party.

There, too, things seemed nearly settled after the March 1 Super Tuesday primaries. Trump dominated, bringing his state victories to 10, just like Clinton.

His rhetoric appeared to shift as a result. He focused more on trade issues, where he is less controversial than some others; he also appeared to back down on torture and killing of terrorists’ family members.

More importantly, his tone seemed to moderate. He spoke several times about wanting to unite the Republican Party as its standard-bearer. “I think we’re going to be more inclusive,” he said in his March 1 election-night speech. “I think we’re going to be more unified. And I think we’re going to be a much bigger party. And I think we’re going to win in November.”

A week later, in his March 8 election-night speech, Trump thanked and offered “great respect for” House Speaker Paul Ryan, spoke about how he could win the general election, and even promised to help party members down the ballot. “It’s very, very important as a Republican that our Senators and that our Congressmen get re-elected,” he said.

But, just like Clinton, he has found the final nails difficult to pound in. With anti-Trump allies making a desperate final effort, he lost both Kansas and Maine to Cruz on the 5th. Cruz later won Idaho and Wyoming too; Rubio picked up Puerto Rico and Washington, D.C.

Trump bounced back with victories last Tuesday, but remains short of a majority of delegates awarded thus far. And some polls have showed Trump’s previous leads dropping in Florida, Ohio, and elsewhere.

With a sense that Trump can still be stopped, his opponents within the party have ramped up their attacks on him. A #NeverTrump online movement is flourishing, along with other signs from party leaders that they will try to wrest the nomination from Trump if he reaches the convention with a plurality, but not a majority, of delegates.

With the goal line moving away from him, Trump has gone right back to threatening Republicans who don’t support him, rather than offering olive branches.

And, late in the week, he abruptly drew all attention away from his primary competitors, by speaking in support of violence against protestors at his rallies. That, unsurprisingly, let to more violence, and more media attention, which drew more attention-seekers, which led to more violence and more attention.

None of which is what you might expect from Trump once he feels confident in the nomination.
That kind of behavior, presumably, would get erased in that Etch-A-Sketch re-start Fehrnstrom spoke of.

That could come very soon, if he sweeps Tuesday; the same is true of Clinton. Both are eagerly hoping so—but both have also found before that the nomination is not as close as it may appear.