Republicans have long done things that are contrary to their stated goals. They want nuclear families with a stay at home mom, but they don't want to pay people enough to do that.
They don't want abortions but they don't want to have education and contraception.
They are neither stupid nor lying. It's so much worse than that.
Conservativism isn't a set of political or moral ideologies. There are zero consistently conservative positions, because conservativism is an irrational function of the human mind. Conservativism is the manifestation of malignant narcissism. Conservatives define their values around their personal identity, and use the party membership to justify their selfishness.
The things they say, they say because it benefits them at the time to say it. The things they want benefit themselves when they want it. When someone else wanting the same thing or saying the same thing is bad for them, it's no longer a good thing.
Reasonable people are often surprised by sudden shifts in priorities, and there are a bunch of memes going back since the dawn of conservativism. To a reasonable person, it resembles hypocrisy or short-sighted stupidity, but it's neither. It is the only common, core principle that unites all conservatives everywhere across time: Is this good for me right now? Of course, when the answer is "no," it's followed by the Bob Rumsen Corollary: "Who is to blame for this?" Spoiler, this set of questions never results in introspection or growth as a person. That is not the conservative way.
I would argue that this behavior you are describing is a kind of stupid. It is self destructive in the long term, and certainly not intellectually rigorous.
Even after Trump’s partial reversal, parents could have to contend with myriad price increases for smaller items, from onesies to blueberries. The Budget Lab, which analyzes the impact of federal policy proposals, has estimated the tariffs announced as of April 2 could cost an average household $3,800 per year, or $73 per week, a cost that could hit families especially hard during the early years of parenthood, already a time of enormous financial upheaval.