The Supreme Court Monoday turned down a request that it delay the 1980 census , scheduled to start April 1, unless illegal aliens are excluded from the count. The delay had been sought by the Federation for American Immigration Reform, the Los Angeles-based Committee for Repsentative Government, and 26 members of Congress. They argued that including illegal aliens would "dilute" the population, which is used as the basis for congressional reapportionment and for the allotment of federal funds to the states.
Also on Monday the Supreme Court:
* Temporarily blocked a lower court ruling that some aspects of the 1977 strip mining act, which requires restoration of mined land to its origi nal condition, are unconstitutional.
* Ordered a former National Security Council aide to respond within a month to the government's appeal of a ruling that Richard Nixon and two former aides conducted illegal wiretapping.
* Refused to block a subpoena for the records of publisher John McGoff for the Securities and Exchange Commission's investigation of allegations that he had ties with South Africa.