US oil production in 2007 was only 5 million bpd.  The US can theoretically double its oil & gas production again in the same way it did from 2008 to 2014 and it did this without any help from the US government.  If Mr. Trump's energy policy is one of removing all obstacles to oil exploration and production then this will happen.  A tax on imported oil will raise the price domestically providing additional incentive for US suppliers to produce more oil.  Of course if the US does apply a BAT, Canada could institute a countervailing duty with imported oil (US and others) but that will never happen as it would affect Mr. Trudeau's Quebec and Maritime supporters.