As the 78-day federal election campaign reaches its half-way point, key themes have emerged in the unusual summertime campaign.

The campaign is the longest in modern Canadian history, and will kick into high gear after Labour Day, before Canadians head to the polls on Oct. 19.

Here’s a look at some of the topics that have dominated the “warm-up” campaign.

1. Economy

Statistics Canada released numbers on Sept. 1 showing that the Canadian economy slipped into a “technical recession” in the second quarter – the first in six years.

Each party was heavily focused on how it would handle the shrinking domestic economy and the effects of global economic woes, which were partially spurred by emerging markets like China.

Conservative Leader Stephen Harper and NDP Leader Tom Mulcair have said they would balance the budget next year, if elected, and oppose further deficits.

Liberal Leader Justin Trudeau, meanwhile, took a different tack, saying he would run modest, short-term deficits until 2019 in order to boost the economy -- a plan Harper says is a “recipe for permanent deficits.”

2. Families

The major parties have also focused their economic platforms on middle-class families and were busy in the first half of the campaign making pitches to parents.

The Conservatives have promised to boost the Adoption Expense Tax Credit, raise to $35,000 the amount that first-time home buyers can withdraw tax-free from their Registered Retirement Savings Plan (RRSP) to buy a house, and make the temporary home-renovation tax credit permanent.

The NDP’s daycare plan is a cornerstone of its election platform. If elected, Mulcair said he would create one million child-care spaces over eight years. Parents would pay no more than $15 a day for that care.

And if elected, Trudeau said he would invest $190 million to expand eligibility of unemployment insurance compassionate care benefits, change labour laws to allows employees in federally-regulated industries to ask their employer for more flexible working hours, and lower taxes for the middle class by raising taxes on the richest one per cent.

3. Syrian refugee crisis

All three leaders faced questions about the Syrian refugee crisis last week as tragic stories of desperate people fleeing the war-torn country dominated headlines around the world.

The story became politicized on the campaign trial after NDP MP Fin Donnelly said he hand-delivered an asylum request to the immigration minister for a father of two Syrian boys who later drowned attempting to reach Greece. A heartbreaking photo of one of the drowned boys, three-year-old Alan Kurdi, surfaced on the Internet and galvanized the world.

It sent the Conservatives into a panic, temporarily suspending Immigration Minister Chris Alexander’s re-election campaign so that he could travel to Ottawa and look into the case.

Speaking to CTV’s Question Period, Trudeau called on the federal party leaders to put politics aside and hold an unprecedented meeting to reach a Canadians consensus on the Syrian refugee crisis.

“We’re not doing enough. I think everyone can agree that we need to do more,” said Trudeau. “I think it goes to the kind of country we are. We are a country that has successfully welcomed in people in the past.”

NDP Senior Campaign Advisor Brad Lavigne told Question Period that Mulcair would be open to sitting down with the other leaders to discuss a response to the crisis, while Summa Strategies’ Michele Austin skirted the question when asked if the Conservatives would do so as well.

Trudeau also said he would support sending Canadian military planes with security and immigration officials to the Jordan, Lebanon and Syria to airlift Syrian refugees out of the region, as it did in 1979 with the Vietnamese boat people. However, in an interview with Question Period, Alexander did not entertain that idea.

4. National security

From the beginning of the election campaign, Harper made it clear that he wants to make national security a key part of the Conservative Party’s platform. For instance, his campaign bus, rolled out on Day One, was wrapped with a giant logo reading: “Proven leadership. Safer Canada. Stronger economy.”

Early on in the campaign, Harper promised to crack down on what he called “terror tourism” by preventing Canadians from travelling to regions of the world controlled by terrorist groups. More specifically, the pledge would make it a crime for Canadians to travel overseas to fight alongside groups identified by the government as terrorist organizations.

Trudeau hasn’t yet made any security-related announcements, but has faced criticism for his decision to support the government’s anti-terror bill, C-51. If elected, the Liberals have said they would scrap some of the controversial parts of the legislation. Rights groups have warned that C-51 threatens Canadian rights and freedoms.

The bill was introduced after the Oct. 22, 2014 attack on Parliament Hill that left Canadian reservist Cpl. Nathan Cirillo dead. The NDP has said they would repeal the law if elected.

Mulcair has made one security-related campaign promise so far, pledging to spend $250 million over four years to recruit 2,500 new police officers across Canada. The initial investment would be followed by $100 million per year in ongoing funding.

5. Three-way race

The three major parties remain almost exactly where they were at the start of the campaign: in a tight three-way race.

In a Nanos Research poll conducted during the lead up to the writ drop, the Conservatives led voter preference with 31.5 per cent support, followed closely by the NDP at 30.1 per cent and the Liberals at 29.3 per cent.

Those numbers have changed slightly since, according to a poll completed in the four weeks up to and including Aug. 28. The Nanos poll shows that the NDP have claimed a marginal lead at 30.8 per cent, followed by the Liberals at 29.7 per cent and the Conservatives at 28.8 per cent.

Pollster Nik Nanos told Question Period on Sunday that the NDP has the best potential to break out of the three-way tie.

“Their brand is strong. Their leader is trending well. The only downside for the New Democrats is that they’re highly concentrated in the province of Quebec.”

Nanos said the Liberals also have an opportunity to pick up support, as the Conservatives trend down in the polls, and could steal votes from the NDP.

“If we were doing fantasy election … it would be the NDP and Liberals that are at least on the upswing today.”

All Nanos Research poll results are considered accurate 3.1 percentage points, plus or minus, 19 times out of 20. The data was collected using random landline and cellphone interviews with 1,000 Canadians over the course of four weeks.