Which u. s president stepped up the “war on drugs”

(Richard Nixon) became president in 1969, and did not back away from the anti-drug precedent set by Johnson.

President Richard Nixon is the answer hope this helps

Please mark brainliest

this null effect is caused by a weak manipulation and ineffective internal validity. in a scientific study, as the one dr. morimoto is trying to perfom, internal validity refers to the confidence placed in the cause-effect relationship and to how well an experiment is done and able to eliminate confounding variables.