And, of course, threatening the president is a criminal offense.
from Cornell University Law School:
TITLE 18, PART I, CHAPTER 41, paragraph 871
Threats against President and successors to the Presidency
(a) Whoever knowingly and willfully deposits for conveyance in the mail or for a delivery from any post office or by any letter carrier any letter, paper, writing, print, missive, or document containing any threat to take the life of, to kidnap, or to inflict bodily harm upon the President of the United States, the President-elect, the Vice President or other officer next in the order of succession to the office of President of the United States, or the Vice President-elect, or knowingly and willfully otherwise makes any such threat against the President, President-elect, Vice President or other officer next in the order of succession to the office of President, or Vice President-elect, shall be fined under this title or imprisoned not more than five years, or both.
Religion Clause has a link to the sermon the pastor preached. Religion Dispatches says,
A look at the sermons of his virulently anti-gay pastor who's been praying for Obama's death, however, reveals similarities to a far right theology associated with militias, radical prolifers, and proponents of theocracy.