Good sources! From the first:
The backlash was swift. The McKinley Tariff proved deeply unpopular with working-class Americans, who saw everyday goods—from clothing to home essentials—become more expensive. In the 1890 midterm elections, voters delivered a landslide defeat to McKinley’s Republican Party, leading to one of the biggest political shifts in congressional history (Stanwood, American Tariff Controversies, 1903). The economic downturn that followed, culminating in the Panic of 1893, only intensified the criticism.
And there was no relief for years. He may have finally decided to try a new policy, but he was shot. So...
Only B4 would attempt to turn McKinley into a popular hero.