THE ideals of liberty and equality for all citizens in a democracy are not always realized - even in a proud democracy like the United States, now celebrating its Constitution's bicentennial. If basic rights were uniformly sustained, pressures would not build in entire communities, such as occurred in the inner city of Detroit, torn apart by riots 20 years ago this week. Detroit, too, had been proud of its record of offering opportunity to ``the workingman.'' It requires uncommon intelligence to perceive racism, and uncompromising moral diligence to rout it. Racism can begin as an unconscious thought, surface as a careless remark. If this were all, there would not be that much to say about racism. But it does not stop there. It infects social, cultural, and occupational systems with an unfairness that deprives ethnic or religious groups of the most basic rights. It can be murderous. It deprives, too, the larger society of the harmony, integrity, and opportunity it seeks. The bigot, deformed by his beliefs, needs as much to be freed of racism's evil filaments as does the victim.
Nathan Perlmutter, national director of the Anti-Defamation League of B'nai B'rith, who died this week, well understood the nature of the warfare against racism. He saw how targets of bigotry - such as blacks and Jews - can unwittingly turn on one another instead of maintaining common cause.
Ignorance is linked to racism, which can make racism appear a passive fault. But subtler forms of racism often reflect conscious, ``intelligent'' thinking gone wrong. These take the most active, persistent resistance to rout.
Few warriors against democracy's internal threat of racism may win the Medal of Freedom, which President Reagan bestowed on Mr. Perlmutter last month. But such dedicated recruits are as needed as any army against an external threat.