Lincoln didn't just casually mention the collection of the federal tariff in his Inaugural Address and his Blockade Proclamation. He discussed the collection of the tariff in relation to a possible invasion of the southern states and a blockade of southern ports. These could be considered threats of war against the south.Thanks for your response.
Of course he did. Again, no one is questioning that. Collecting the tariff was an important responsibility of his Administration. The issue arises not because Lincoln mentioned it, but because some call it "the deciding factor".