The easy part is whether there is copyright protection: yes. It does not matter whether the quotes are in a newspaper, a personal blog, a hardbound book, or on TV; it doesn't matter if the interviewee is right-wing or left-wing or wingless. An interview is protected by copyright. The question is, who holds that right, and in what exact manner? The interview could be a collaborative work; it could be a joint work; it could be the property of the interviewer.
In Taggart v. WMAQ, the court points out that for a work to be protected (sect. 101 of the copyright act), it must be
‘fixed’ in a tangible medium of expression ... or otherwise
communicated for a period of more than transitory duration.
which interviews are not (assuming the answers were not pre-written). See also
Falwell v. Penthouse.
The interviewer would own copyright to the compilation of quotes, see for example Quinto v. Legal Times of Washington
Regardless of who owns the copyright in each of the quoted passages in
the article, there can be no doubt that Quinto owns the copyright in
his compilation of the quotations
As to ownership of the quotes themselves, Suid v. Newsweek Magazine observes that
The author of a factual work may not, without an assignment of
copyright, claim copyright in statements made by others and reported
in the work since the author may not claim originality as to those
statements
and Harper & Row v. Nation Enterprises, 471 U.S. 539 likewise states that
an author may not claim copyright in statements made by others and
reported verbatim in the author's work
What we get from this is that the interviewee cannot claim infringement by the interviewer (they could however claim some form of breach of contract, depending on what the parties agreed to in carrying out the interview), that the interviewer does own copyright of the interview, but not the specific quotes from the interviewee. This leaves unanswered a core question: can an interviewee claim control over their quotes and deny permission to reproduce the quotes? An alternative would be that the quotes are "data" which are in the public domain. I find the latter outcome extremely unlikely, but at any rate, I know of no case law on point.