Canada has had sky high tariffs on American goods for decades, some as high as 250%. Trump is trying to level the playing field. Canada currently has an imbalance of trade with us of about $50 billion. Trump would like them to get that down to around $30 billion.
In the past, even Nancy Pelosi and Chuck Schummer agreed we needed more reciprocal tariffs. Other nations of the EU, the UK, Japan, Vietnam, South Korea and of course communist China, have had similarly high tariffs on us.
These tariffs have put American workers at a disadvantage all these years.