In the most recent (nonbinding) 2020 referendum, Puerto Ricans voted for statehood by a 52.5% to 47.5% margin. Including abstentions, the margin was 50.8% to 49.2%. And of course, you have to account for the fact that nearly half of eligible voters didn't vote. But in any case, the views of Puerto Ricans seems to have only slightly shifted since the 1998 plebiscite where statehood was defeated 50.3% to 46.6%.
Several commentators and at least one senator have suggested admitting Puerto Rico as a state in the coming Congress, when Democrats will have control of both chambers. My question is, has there ever been a case of Congress admitting a U.S. state where there were such high levels of internal disagreement within the would-be state?
(For the sake of argument, let's posit that support for statehood in Puerto Rico is a majority but not a supermajority, i.e. 55% for and 45% against, and a hypothetical binding referendum would have a similar breakdown)