Andrea Horwath's New Democrats have made significant gains in the polls since the Ontario election campaign kicked off a little more than two weeks ago. Though Doug Ford's Progressive Conservatives are still in a better spot to win the most seats, the possibility that the NDP will form the next government in Ontario is quite real.

It's like 1990 all over again. Or is it?

In 1990, the Ontario New Democrats formed government for the first and only time in their history. But the campaign did not start out with Bob Rae's party as the favourite.

Far from it — the incumbent Liberals under David Peterson had a 24-point lead over the NDP in a June 1990 poll conducted by Environics.

Peterson had won a majority government only three years earlier in 1987, in an election that left the NDP as the Official Opposition and reduced the Progressive Conservatives to third party status.

Peterson didn't need to call an election for the summer of 1990. His decision to send Ontarians to the polls early started his campaign on the wrong foot. On Sept. 6, 1990, Peterson lost the premiership.

Is the same pattern shaping up for Horwath's New Democrats? While there are some parallels between the 2018 and 1990 election campaigns, there are also some important differences.

Big NDP gains in the polls

The most obvious parallel between the two elections is the significant gains the NDP has made in the polls. From the 26 per cent the NDP scored in June, 1990, the NDP rose to 34 per cent — just six points behind the Liberals — in an Environics poll for the Toronto Star conducted at the end of August, 1990.

The final poll of the campaign, conducted by Angus Reid for Southam News, put the New Democrats ahead by four points with 38 per cent — which is just about where they ended up on election night. The NDP had picked up about 12 points in the course of the campaign, while the Liberals lost 18 points.

As of the May 24 update of the CBC Poll Tracker, Horwath's NDP has gained more than nine points since the campaign began. The PCs have slipped four points and the Liberals have dropped five over that time.

The trend line for Ontario New Democrats in 2018 looks eerily similar to what we know about the campaign's progress in 1990.

Actually, we know a whole lot more about the ups and downs of the 2018 campaign to date than we did about the 1990 campaign at the time. So far, a dozen polls have been conducted since Ontario's current election campaign officially began on May 9.

But in 1990, only two polls were published during the entire campaign — meaning that the NDP's early momentum was happening quietly, in the absence of poll coverage, and was not the product of a bandwagon movement that the polls helped create.

Unpopular options

Another parallel between the two elections is the unpopularity of the alternatives.

Liberal Leader Kathleen Wynne began the campaign as the country's least popular premier and 83 per cent of Ontarians say they want change, according to an Abacus Data poll. The same poll found that 46 per cent of Ontarians have a negative impression of Ford, while just 26 per cent report holding a positive one.

Horwath, by comparison, is seen as more positive than negative by a margin of 42 to 13 per cent.

Ontario NDP Leader Andrea Horwath has seen her party make significant gains in the polls since the start of the Ontario election campaign. (Chris Young/Canadian Press)

Though Peterson started out in 1990 with high popularity, his campaign sapped it. In the days after the vote, just 12 per cent of Ontarians thought he was the best person to be premier, down from 39 per cent before the campaign had begun.

Mike Harris, newly minted leader of the PCs, scored even lower. And his party had been in power for 42 uninterrupted years between 1943 and 1985; voters weren't ready to go back to the PCs after only five years.

It was a good opportunity for the NDP to present itself as the best alternative.

There are some important differences between then and now, however: Ford is not the incumbent premier, Horwath is not the Official Opposition leader and Wynne is not the least experienced of the leaders on the hustings.

The New Democrats are competing with the PCs to be the 'agent of change' in 2018. In 1990, they were seen as the only palatable option.

The efficiency gap

​Despite the relatively close margin between the PCs and the NDP in the polls, the Poll Tracker still heavily favours the PCs to win a majority government.

This is because the PC vote is more efficient — the party has a better base of support and is ahead in the Greater Toronto Area, where nearly half the seats in the province are located.

The projections suggest that for the New Democrats to win even a slim majority, they may need a lead of three to five points over the PCs provincewide.

In 1990, however, the New Democrats won a comfortable majority — nearly 40 seats ahead of Peterson's Liberals — despite beating the Liberals in the popular vote by only five per cent.

One of the factors contributing to the NDP's 1990 majority win (something even Rae at the time didn't see coming) was the presence of two small right-wing parties.

The Family Coalition and the Confederation of Regions (COR) parties combined for nearly five per cent of the vote provincewide in 1990. In 11 ridings, the combined vote of the Family Coalition and the COR was greater than the margin between the losing PC and winning NDP candidates.

Had enough of these votes gone to the PCs instead, the NDP would have fallen just short of a majority. The split on the right made the NDP's vote more efficient than it otherwise would have been.

Though there are several smaller right-of-centre parties running in this election, none are expected to have the same kind of impact. If they did, the NDP's chances of winning a majority government in 2018 would be better.

A new generation of voters

The memories of the 1990 election — and the subsequent five years of Rae's NDP government — are beginning to fade. Millennials will be the biggest cohort of eligible voters in this election, and even the oldest among them would have been roughly 15 years old when Rae's government was defeated in 1995.

About a sixth of the Ontario electorate today wasn't even been born yet in 1990, nearly a quarter were barely out of diapers and over 2 million Ontarians came to Canada as immigrants after 1990.

So for a significant portion of voters, Ontario's only NDP government is a history lesson rather than a lived experience. Those voters who might be negatively influenced by memories of the early 1990s would be predisposed already to shun the New Democrats. The party traditionally has struggled to win support among older voters, so it's difficult to separate the tendency of those voters to eschew the NDP from any lingering memories of 'Rae Days'.

In the end, the Ontario election will not be decided by what happened over 20 years ago. But some of the factors that led to that historic breakthrough in 1990 run parallel to the NDP's rise today. Can the party look forward to a similar outcome on June 7?