MANILA — IN the past, political baron Luis Singson and his private army presided over one of the Philippines most vicious provincial battlefields.But that has changed, says the strongman of Ilocos Sur province in northern Luzon island. "Before, my province had a lot of killings and was the most notorious," he says. "Now, it's considered one of the most peaceful." "If you rule through fear, your leadership is only temporary," he adds. "The only way to rule long is through the love of the people." Still, Mr. Singson, who is widely blamed for assassinating his main political rival in a church in 1970 but claims to have survived six ambushes himself, isn't taking chances on popularity. His luxurious Manila flat is guarded by a phalanx of guards, part of what is still one of the country's most powerful militias. "People say I have a private army, but they're actually my security forces and I need them," he said. "The only way to beat me is to kill me." As the Philippines ready for a contentious election season, the need to wrest politics from the grasp of strongmen becomes urgent, diplomats here say. Presidential elections begin next May, but already the political temperature is climbing with the legal confrontation between President Corazon Aquino, who insists she won't run again, and the ambitious former first lady, Imelda Marcos. Mrs. Marcos, who faces criminal charges for tax evasion and corruption, also confronts a bitter rivalry with loyalists of her late husband, President Ferdinand Marcos, who aspire to succeed Mrs. Aquino. Even with high levels of discontent, a backslide into warlord days is not imminent, political observers say. But they note the country has regressed since the heady days of 1986, when a popular uprising swept Marcos from power and bore Aquino into office. "We need to change our political culture," says Florencio Abad, a former Cabinet minister who split with the Aquino government and now heads a nongovernment aid organization. "The relationship between the political leaders and the people is still feudal," he continues. "In this country, there is no such thing as a political party. What remains are the political clans." Yet government and private officials contend that change is afoot. In 1992, more than 80 percent of the country's 45 million voters will be under the age of 44; more than 50 percent will be under age 30. Young voters could shift allegiance away from older powerful families, analysts say. The influential Roman Catholic Church is also throwing more of its weight behind political reform in what many observers see as a serious challenge to traditional political patrons. Volunteer groups and community organizations, normally apolitical, are assuming a more activist profile. "If harnessed properly, they can become critical swing votes," Mr. Abad says. In this context, the prospect of pistol power in next year's election stirs unease. According to National Security Council figures, there are as many as 800,000 unregistered weapons in the Philippines. "We are prisoners of violence even in our own homes," says Reynaldo Pacheco, a retired official of the Asian Development Bank and gun-control advocate. The government vows to crack down on election mayhem. The Commission on Elections is carrying on a voter education program to heighten public awareness and lessen fraud and intimidation. And the Army and national police have pledged to help enforce a ban on the carrying of unlicensed firearms and limits on activities of bodyguards or militias. "We are going to be much stricter than we have been in the past," says election commissioner Christian Monsod. "The politician who thinks he can do it with money or goons is in for a big surprise." Reformers, however, are up against some of the most powerful clans in the country, observers say. As the election approaches in troubled economic times, money, muscle, and patronage could once again prevail. When she came to power almost six years ago, Aquino pledged to rein in private armies. But her effort has been tabled after seven coup attempts and the recent alliance of her younger brother, Jose Cojuangco, with former Marcos allies and traditional politicians. Mr. Cojuangco is widely believed to maintain a private army on Hacienda Luisita, the family's estate in the central Luzon province of Tarlac, which has often been a battleground between his political forces and those of his cousin, Eduardo Cojuangco, a presidential aspirant. The Marcos stronghold, Ilocos Norte in northern Luzon, also bears watching. There, feuding Marcos stalwarts vie for the attentions of Marcos' son, Ferdinand Jr., a former provincial governor whose return could trigger what one analyst calls "the battle for the Marcos legacy."