If we judge American presidents by how the poor fare under their administrations, then President Reagan's record looks dismal so far, says Washington consultant Charles A. Murray. But his verdict is equally harsh on the man who launched the War on Poverty, Lyndon B. Johnson.
Mr. Murray, a poverty-program specialist, has put a flock of unorthodox views into a booklet, ''Safety Nets and the Truly Needy,'' for the conservative Heritage Foundation.
An unabashed fan of the trickle-down theory of wealth, he blasts the War on Poverty mentality for leaving the poor in worse shape than it found them. And he blames the Reagan administration for failing to reform the welfare system. Among his views:
* Americans should bring back the old stigmas put on able-bodied people who collect welfare. During the 1960s, a guilt-ridden and properous country developed the idea that society, not the individual, was to blame for poverty, holds Murray. Being on welfare grew more socially acceptable, he says.
* The derided and rejected trickle-down theory of wealth is exactly what the country needs. Murray recently told reporters that the Reagan administration should ''quit being apologetic about it.'' Poverty rates go down only as the economy expands, pulling up all segments of society, he says.
He argues that the percentage of US poor began dropping, not after the antipoverty program of the late 1960s, but during the economic boom of the 1950 s. As the economy stalled in the 1970s, so did progress toward reducing poverty , he says.
* Job-training programs fail miserably because they enroll ''people who are not prepared to help themselves.'' Job habits hinge almost entirely on upbringing, he says.
Murray is calling for a total overhaul of the welfare system, beginning with converting all federal welfare to cash payments.
He would halt all federal welfare except that going to the ''truly needy'' - the disabled poor, elderly, and jobless. He opposes welfare for the ''working poor,'' he says, because such aid encourages dependence.
Finally, he would build in more rewards for achievers. Job programs would no longer focus on school dropouts but would rather enroll young people from poor areas who have good school attendance records.