Yes it will take time and that's his ultimate goal. Tarrifs are a start which will start making it more expensive for companies to manufacture outside the US to sell into the US, proposed tiered corporate tax rates with lower rates for portions or goods manufactured in the US, proposed tax rebates for buying cars manufactured in the US. The goal is to force companies to bring manufacturing back to the US and the second phase after NAFTA which encouraged companies to bring back to Canada and Mexico.
Looking at the recent announcements by companies saying they will invest in the UK it seems to be having the desired effect. Will it take time yes but rebuilding manufacturing in a country will always take time and lots of investment. Apple has committed to spending $500bn, Hyundai, Softbank etc have all made public commitments to invest in the US. Compare that to the economic news out of the UK where the priority is what benefits we cut and keep.
I don't like his approach but he is doing what he said he will do and he has been talking about this for ages, there a video online where he was probably 40 years old or so saying the exact same thing.
Canada dairy tarrifs has nothing to do with quality and everything to do with political support for the liberals. The dairy industry has a strange hold on the liberals and in turn they try to protect them for continued support.
He is right that the US needs to prioritize itself and focus on fiscal responsibility. The US spends way too much on debt now, $800 bn on interest annually, $2 trillion budget deficit, that's ridiculous and unsustainable and Washington needs major change from the spend like drunken sailors approach.