He was the only "survivor" of the Liberal Party who made it to the
senate, where he was inevitably singled out by Marcos and his allies as
their greatest threat. In 1968, during his first year as senator, Aquino
warned that Marcos was on the road to establishing "a garrison state"
by "ballooning the armed forces budget", saddling the defense
establishment with "overstaying generals" and "militarizing our civilian
government offices"all these caveats were uttered barely four years
before martial law.

President Marcos declared martial law on September 21, 1972 and he went
on air to broadcast his declaration on midnight of September 23. Aquino
was one of the first to be arrested and imprisoned on trumped-up charges
of murder, illegal possession of firearms and subversion. He was tried
before Military Commission No. 2 headed by Major-General Jos Syjuco. On
April 4, 1975, Aquino announced that he was going on a hunger strike, a
fast to the death to protest the injustices of his military trial. Ten
days through his hunger strike, he instructed his lawyers to withdraw
all motions he had submitted to the Supreme Court. As weeks went by, he
subsisted solely on salt tablets, sodium bicarbonate, amino acids, and
two glasses of water a day. Even as he grew weaker, suffering from
chills and cramps, soldiers forcibly dragged him to the military
tribunal's session. His family and hundreds of friends and supporters
heard Mass nightly at the Santuario de San Jos in Greenhills, San Juan,
praying for his survival. Near the end, Aquino's weight had dropped
from 54 to 36 kilos. Aquino nonetheless was able to walk throughout his
ordeal. On May 13, 1975, on the 40th day, his family and several priests
and friends, begged him to end his fast, pointing out that even Christ
fasted only for 40 days. He acquiesced, confident that he had made a
symbolic gesture. But he remained in prison, and the trial continued,
drawn out for several years. On November 25, 1977, the Commission found
Aquino guilty of all charges and sentenced him to death by firing squad.
However, Aquino and many others believed that Marcos, ever the shrewd
strategist, would not let him suffer a death that would surely make
Aquino a martyr.