But a law may be passed making better, in a sense, some previous act. That is, an unforseen but imperative necessity may call for the doing of something which is not unlawful, but which needs, yet has not received, the sanction of law. This act may afterwards be legalized by the legislature.
The things forbidden by this clause would, if permitted, render unsafe all those personal rights for the security of which the constitution was framed and the government founded.
Clause 4.—Direct Taxes
No capitation or other direct tax shall be laid, unless in proportion to the census or enumeration hereinbefore directed to be taken.
This clause emphasizes the first sentence of clause three, section two, of this article. It was intended to prevent the taxation of the two-fifths of the slaves not enumerated for representation, and was evidently inserted as a concession to the slave states. But the abolition of slavery takes from the clause all force except that mentioned at the beginning of this paragraph.
No capitation tax (that is, so much per head) has ever been levied by the general government.
Clause 5.—Duties on Exports.
No tax or duty shall be laid on articles exported from any state.
This was designed to prevent discrimination against any state or section.
Though the question has never been judicially determined, it is generally understood that since anything exported must be exported from some state (or territory), this clause prohibits all export duties.