Driving down costs is always a good thing, but if we can do that so can the Mexican government.
So, I think there is a psychological impact of a tariff. Start low and threaten high.
A repeal and renegotiate NAFTA is also a way to achieve balance.
But I am adamant that we want ALL of our manufacturing jobs and products here. If they weren’t a benefit, Mexico wouldn’t want them there.
Tariffs alone won't do it. Here's a real world story that I will share to illustrate why I say that.
I was at a shipbuilder in California getting a tour. They are the last shipbuilder left in the state. As we walked through the yard, they brought us to a paint shop. They told us that the environmental regulations in California were so tough that they had to build a multi-million dollar facility to spray paint their parts, with filters and controlled air sources and self contained runoff and all that. In other yards I've seen, it's a shed and I said so. Guy walking us through the yard said "yup, that's why nobody build ships or aircraft in California anymore".
California is the extreme case. But over time the nation has been following it into manufacturing graveyard thanks to federal level regulations getting ever more California-like. We can put crushing tariffs on products but some industries will just go out of business because the capital needed to comply with these onerous regulations if they moved their operations back to the US is prohibitive.