Comment by OgsyedIE
A Japanese commentator on a place I follow elsewhere remarked that the single biggest fault in party politics are the politicians who think the international market that buys Japanese services are a black box for receiving national income that they never have to worry about it going away even though it's been diminishing and losing reliability for several years already. Does this reflect what you see?
Observationally, there are many systems in Japan that place disproportionate value on international income and demand. Some of them are supported by data and others are not. I think that international markets are a relatively good place for Japan to focus, but it is the case that particularly with the US levying tariffs on Japan, people are now questioning this status quo more. In the spaces I'm familiar with, there is ample market data to show overseas growth, but this mostly focuses on Japan's historical market exports, like culture and IP. Almost on a yearly basis, there is some meaningful cultural export that Japan is able to export quite effectively. Japanese companies, who previously would have licensed this to an overseas distributor or team of companies are starting to move in house. The most prominent example of this is Sony acquiring Crunchyroll, Funimation, and RightStuf, all of which contribute to Sony creating a vertically integrated anime production stack, with Aniplex owning end-to-end domestic-to-overseas production, merchandising, and distribution.
There is definitely room to be worried, but the increase in tourism (perhaps, one might refer to it as "overtourism") supports the credence that there are valuable elements of Japanese culture that have demand overseas.
I think the more you stray from traditional mainstay IP and culture exports, the more unreliable it is. Again, a notable prolific example is Nippon Steel attempting to gain profit from operating US Steel, rather than simply taking market share.
On the topic of tariffs, though, I would definitely say that many Japanese people are upset about the tariffs, first directly at the US, and second at Ishiba for not negotiating a lower tariff rate. But here the sentiment is that the tariffs themselves are not only unjustified, but also deleterious to the US-Japan relationship. Japan is rather unique in the aspect of being militarily-tethered to the US, and the US has asked it to make uncomfortable (and difficult to gain large support for) economic investments in its own JSDF for the US's benefit. Subsequently, the tariff impact makes the LDP's position quite upsetting, because the LDP failed to negotiate tariffs and more-or-less shoved the military changes through with the intention of strengthening ties with the US.
So, there are a lot of things at play, but the current economic winds and the international relationship with the US has definitely skewed people towards isolationism and made it difficult for the LDP to retain the support they have.