I think the polls, in this case, are misleading for two reasons.
1. There has been major flight of Trump-opposed conservatives and moderates from the Republican Party. I’ve yet to see a poll that attempts to take this metric into account. There’s no telling how much the reported percentages would shift if these former Republicans returned to the party to vote for a primary challenger.
2. I think there’s an inverse of what happened in 2016 going on in these polls. In 2016, support for Trump was under-reported because those being polled didn’t admit to supporting him. Now, I think a lot of people who are more on the rocks then they appear are sticking with Trump when being polled so as to not “aid the leftist media narrative” while still harboring more doubts than they’ll admit.
Ultimately, I believe Trump’s core supporters are where it’s always been: around 35% of self-described conservatives.