Private-sector membership was 5.9 percent in 2025 against 32.9 percent in the public sector, where recognition rules and employer behaviour differ substantially. Supporters treat that gap as evidence that the legal environment, not worker demand, drives the outcome. Opponents argue the comparison proves less than it appears, since public employers face no competitive pressure, cannot relocate, and have different incentives to resist, which explains much of the difference on its own. How much of the gap is legal and how much is structural has never been cleanly separated.