WHERE THE CANDIDATES STAND ON DRUGS. The United States is awash in illegal drugs; many Americans even regard them as a threat to national security. Fifth in a series on the candidates and the issues. BUSH

BACK in April, George Bush was on the run on the issue of illegal drugs. The topic was bursting onto the top of the list of concerns in national polls, and voters were blaming President Reagan and his vice-president for not doing enough about it. Adding to Mr. Bush's burden was the administration's failed attempt to oust Panama's Gen. Manuel Antonio Noriega after his February indictment in Florida on charges of drug trafficking.

But today the vice-president seems to be winning his way back to the good side of many voters on the drug issue.

Bush has distanced himself from some Reagan policies, and adopted a harder line. He vigorously advocates the death penalty for drug dealers in certain cases.

The issue of capital punishment is the major distinction between Bush and his opponent, Gov. Michael Dukakis, when it comes to illegal drugs. Save for Mr. Dukakis's objection to the death penalty, both men back a whopping antidrug bill (Senate version: $2.6 billion) nearing completion in Congress. A final bill should be ready next week.

Early in the presidential race, Bush moved away from what Democrats charged was a spotty and inconsistent Reagan-Bush record on the drug issue.

Perhaps in a tacit response to the unsuccessful pressure on General Noriega, and the fact that the Panamanian strong man was on the Central Intelligence Agency's payroll for years (including the period when Bush headed the agency), Bush's drug-policy fact sheet states: ``George Bush will never pay off or bargain with drug smugglers.''

Bush outlines a four-pronged strategy on illegal drugs, an effort that would be led by running mate Dan Quayle as head of a Cabinet-level council:

Education. The vice-president says he would ``establish `zero tolerance' as an attitude and a way of life'' for children through school programs spanning kindergarten through college.

Drug treatment. Bush would encourage drug abusers to seek treatment, and he advocates linking federal drug-treatment funds to the success rate of state and local programs.

Supply reduction. Bush wants to call a summit meeting of all Western leaders on the issue, create an international strike force to destroy drug crops and laboratories, and help drug-producing countries put crop-substitution programs in place. He would replicate the South Florida Task Force, a drug-interdiction program he headed, in other parts of the country.

Tougher enforcement. Bush wants stiff, mandatory penalties for dealers, and such sanctions as suspending driver's licenses or passports for other drug-related crimes. He supports the death penalty for ``drug kingpins,'' defined as traffickers who murder. He would make drug tests a condition for paroling federal prisoners.