But like conservative politicians in other parts of the world, including the UK and France, Canada's have come to recognise ethnic voters could make a real difference at the polls on October 14, especially in and around the three biggest cities, Toronto, Montreal and Vancouver.
Canada takes in close to 250,000 immigrants each year, more than any other industrialised country relative to its population.
According to the Organisation for Economic Co-operation and Development, 18.2 per cent of Canada's 33m inhabitants were born in another country. The figure for the US is 12.2 per cent, and for the UK just 4.8 per cent. The 2003 United Nations Human Development Report estimated that Toronto had more residents born outside the country than any other city in the world, except Miami.
The top four countries of origin in recent years have been China, India, the Philippines and Pakistan. But many urban neighbourhoods also have big enough Italian, Portuguese, Ukrainian and Somali populations for politicians to take notice. Forty members of parliament were born outside Canada.
Immigrants have traditionally been loyal Liberal supporters, but that solidarity has begun to crumble. Shylee Someshwar, director of a Toronto IT consultancy who attended the Indo-Canadian Chamber of Commerce lunch, said that immigrant entrepreneurs had grown to appreciate a party that promoted deregulation and small government.
Mr Harper constantly reminds audiences of the steps his government has taken to help newcomers adjust to their surroundings.
It has pushed up spending on settlement programmes, halved the immigrant landing fee, and set up an office to help newcomers gain recognition for overseas education and professional credentials, a big hurdle for many.
The Liberals are not far behind, promising to raise immigrant quotas and make it easier for temporary workers and students to apply for foreign residence.
Stéphane Dion, the Liberal leader, noted "immigration will account for all of Canada's net labour and population growth during the next five years, and is a key element of the Liberal plan for Canada's future success".