There's an old joke about politics in Kamala Harris's home state, where election campaigns, for various reasons, rarely ever include large political rallies.

"A California political rally is three people standing around a television set," says Dan Schnur, a political communications professor at the University of Southern California, sharing the classic gag.

His point being that the U.S. vice-president had little experience addressing boisterous partisan crowds until just a few years ago.

That's doubly true given her career trajectory, which consisted mainly of being a prosecutor, and then her state's top justice official, one of the less-partisan roles in government.

What a remarkable transformation this week will underscore.

She is headlining a marquee event in American politics, the Democratic convention in Chicago, that begins Monday and culminates three nights later with her accepting her party's presidential nomination.

It's a politically critical audition: A moment to present her case to a country that might not know her, or her policies, especially well.

"There's a real TBD element here that we're all watching," says Christopher Cadelago, who has covered Harris for years as a longtime political reporter in California. He is now Politico's bureau chief in the vice-president's home state.

She has yet to undergo key tests of a traditional campaign due to her unusually late entry into the race: No sit-down media interviews or debates so far, and she's only just started unveiling a platform.

What's clear is her party is suddenly more enthused. Since U.S. President Joe Biden's retirement announcement, Democrats are enjoying better polls, drawing bigger crowds, and raising far more money.

Some credit Harris's performance on the stump. Many in her own party have been surprised by her in one respect: Her public speeches.

"She's exceeded expectations," said Bruce Cain, a political scientist at California's Stanford University.

"You're going to find a lot of people in California saying, 'Oh wow – we never noticed that about her.'" 

Cain credits the stage experience she's gained as vice-president, after less than one term in the U.S. Senate. "Her four years [as VP] were used wisely," he said.

Now here's what we don't know: Her full platform, and how well she'll sell it in unscripted moments, like her upcoming debate against Donald Trump on Sept. 10.

She has jettisoned promises from her ill-fated 2020 primary campaign, where she vied for progressive votes without success.

Harris no longer talks about banning oil fracking; ending private health insurance; reducing police budgets; or extending public benefits to undocumented migrants.

That speaks to the scouting report on Harris from a retired reporter from California who knows her: Very smart, very friendly – and, when it comes to issues, "a bit of a weathervane."

"She could change her mind if the polls aren't with her," says Hank Plante, a now-retired San Francisco TV reporter.

Her policies: What we know

This hardly makes her unique in politics. Look no further than Trump – who used to be pro-choice, then appointed U.S. Supreme Court judges who ended the constitutional right to an abortion.

In Plante's view, it's also a positive attribute to adjust your politics to the moment: "She's smart enough to do that," he said.

We'll know more about the rest of her program soon. She promises to roll out her other economic policies within a few weeks.

She's just released parts related to lowering living costs. The mere act of putting out some policy meat gave her opponents a new political bone to chew on.

Some parts of her cost-of-living plan were well-received or uncontroversial. For example, she wants to reintroduce, and expand, a child-tax credit (a bit like the one Canada has) which existed temporarily as part of Biden's pandemic-relief law. She will also push Congress to pass tax incentives for home construction, and use existing competition laws to block grocery-industry mergers that might limit consumer choices.

Other parts of her agenda are more hotly disputed.

Her proposed $25,000 US for first-time homebuyers has drawn some pushback – with critics contending it would just drain public money, and increase home prices.

But by far the most hotly contested is among the least detailed: A vaguely worded promise to advance the first-ever federal ban on price-gouging for food.

It's been likened to the failed price controls of the 1970s; criticized even by sympathetic analysts on the left; and has the Trump campaign calling her nothing less than a communist.

WATCH | Harris promises Americans economic relief: 

Harris promises Americans economic relief, accuses Trump of serving the rich

U.S. vice-president and Democratic presidential nominee Kamala Harris promised a ban on food price-gouging and more economic opportunities for the middle class at a North Carolina campaign event where she accused her Republican rival Donald Trump of serving the billionaire class.

A puzzling thing about this debate is its utter lack of clarity – about what she's proposing, whether it takes a law in Congress, whether it has any chance of becoming law.

And, frankly, how any of this is different from price-gouging laws that already exist which have already been enforced in different places, including in the not-remotely-communist state of Texas.

Trump himself targeted price-gouging in medical goods during the pandemic.

Harris might have a chance to explain this in more detail if, or when, she sits for a media interview, or in her debate next month with Trump.

Which parallel: 1992 or 1968? 

She did debate on occasion in her early political career. In fact, she may owe her political survival to a moment from a debate in the 2010 race for California attorney general.

Her Republican opponent answered, honestly, that he intended to double-dip in his public salary: to keep collecting a prosecutor's pension, atop the $150,000 US he'd earn as AG. He said he'd earned it, then called the $150,000 salary "incredibly low."

Her team made an attack ad out of it.

This almost certainly made the difference given how close he race was; her opponent even accidentally declared victory on election night, and the San Francisco Chronicle reported the wrong result. It took weeks to name Harris the winner.

"The rest is history," Cadelago said.

Her encounter with history, however, follows a miserable 2020 presidential run, when Harris dropped out before the 2020 calendar year even started.

Contemplating that disastrous past race, Cain brings up another young political star who flopped in his first foray on the national stage.

Bill Clinton gave a boring, interminable speech at the 1988 Democratic convention where the crowd talked over him and pundits declared his career over.

Four years later, he was elected as the 42nd president and was heralded as a stellar orator.

As for whether Harris has the potential to enjoy that upward trajectory, Cain said, we'll know soon enough: "She certainly has improved enormously."

It's a far more enviable historical precedent than what happened to another Democrat in 1968.

Hubert Humphrey was also vice-president, like Harris. His boss, Lyndon Johnson, also cancelled his re-election campaign, and he replaced him. The convention was also held in Chicago.

It was marred by anti-war protests and a violent police response. Humphrey left the convention a damaged candidate – he trailed in the polls, his party was divided. 

"Chicago was a catastrophe," Humphrey later told author Theodore White.

On a week where Gaza antiwar protests are planned in Chicago – some promising a family-friendly atmosphere, others urging violent confrontation with cops – we'll soon learn which historical parallel rings truer.