In Buckley v. Valeo, Rehnquist wrote that:
[N]ot all the strictures that the First Amendment imposes upon Congress are carried over against the states by the Fourteenth Amendment, but rather that it is the 'general principle of free speech that the latter incorporates.
This statement is more or less indicative of his position on incorporation, and indeed on the relationship between federal government and the states in general. He was arguing that the protections of the Bill of Rights (in the case of Buckley v. Valeo, the First Amendment) were not automatically binding on state laws through the Fourteenth Amendment. On the other hand, he did not completely reject the idea of incorporation, and his critics could point out that when the civil liberties being violated at the state level were those supported by conservatives, that he generally tended to cite incorporation. In any case, his retreat from the incorporation doctrine was part of a turn from what conservatives called the "judicial activism" of the Warren Court.