https://www.thegatewaypundit.com/2018/09/bombshell-president-trump-was-right-obama-must-have-signed-off-on-fisa-warrant-to-spy-on-trump/
President Obama would have had to approve the Carter Page warrant per law in order for the spying to proceed without a court hearing. The rule is described on page 7 of 1978 FISA Act!
The Act reads as follows –
“AUTHORIZATION FOR ELECTRONIC SURVEILLANCE FOR FOREIGN
INTELLIGENCE PURPOSES
SEC. 102. ø50 U.S.C. 1802¿ (a)(1) Notwithstanding any other
law, the President, through the Attorney General, may authorize
electronic surveillance without a court order under this title to acquire
foreign intelligence information for periods of up to one year
if the Attorney General certifies in writing under oath “
BOOOOOOOOM!!!!