I would assume he is banking on the following equation going in his favour. He promised the rust belt jobs, if he gets them jobs the extra cost on products will be so diluted across the board your average American will barely notice. Those in the rust belt though! they will feel it positively, their friends and family's will benefit to. So i think the goodwill and votes earned from that will outweigh any negative feelings towards him.
If you think of it when you are at a shop and they say "oh this is x amount"and you think "robbing bastards" who do you blame? you almost hold the poor assistant personally responsible for this outrage don't you, i know i do xD You get my point though, tenuous links from those who shape policy and tax rates are rarely taken into consideration with cursory thought. You blame the company who made it or the shop who you feel are charging to much. The faceless bugger in Brussels who has a meeting we are not privy to or allowed to see the minutes from (legally you have a right to see them but you try going to get them) who just signed some paper that really did affect your end cost never gets a finger pointed at them.