WASHINGTON--The Philippines is the latest case in point: Ronald Reagan can change his mind.

While awaiting a report from special U.S. envoy Philip Habib, the President already has shifted his analysis of the election in Manila.

After telling the nation Feb. 11 that fraud and violence may have occurred "on both sides," Reagan directly blamed the party of President Ferdinand E. Marcos five days later for most of the irregularities.

When Habib returns next week, the shift could pick up speed. U.S. aid could be reduced, Ambassador Stephen Bosworth recalled or Marcos urged to arrange his own succession or to share power with the opposition.

"We have a stake in freedom, we have a stake in democracy," Secretary of State George Shultz told the Senate Budget Committee on Wednesday. "Let's put that first, even above the bases."

He referred to Clark Air Base and Subic Bay, the main forward point for the U.S. Navy's Pacific fleet.

The embattled Marcos had drawn a rare bit of strength from Reagan's initial evenhanded remarks. Marcos' opponents were said to be dispirited by the suggestion of fraud in challenger Corazon Aquino's camp.

Reagan's reversal added to Marcos' mounting woes. His opponents drew encouragement in their effort to drive him from office.

White House aides said the president had been getting more information all the time. But that may not explain the shift in emphasis. With Reagan, who has a long history of pragmatism despite a deep-seated conservative philosophy, it's often hard to tell.

He may have changed his mind about Marcos and the way the election was conducted. He may have been persuaded by the stream of moderate-to-conservative Republicans on Capitol Hill who are lining up against Marcos and would hold up U.S. aid to the Philippines.

A Marcos victory in a demonstrably clean election would have appealed to the President. The Philippine leader represented a known quantity and the stability Reagan prizes in the strategic Pacific region.

But the furor over vote-rigging and Marcos' reluctance to agree to reforms posed an embarrassment to the politician in the White House and sparked disorder in Manila. So Reagan could be getting ready to cut Marcos off.

In foreign policy, Reagan evidently subscribes to an old rule of diplomacy: never admit you are changing your position even while you are changing your position.

On the international front closest to home, however, Reagan is standing firm. His policy on Nicaragua remains based on the judgment that the Sandinistas are Communists posing a threat to U.S. security.

Despite reservations in Congress about the fidelity of the insurgent Contras to democracy, Reagan is determined to help them blast their way to power, or at least a share of it.