The reaction to Sen. George Mitchell’s abrupt announcement that he will not seek re-election is sending a powerful message that works for both sides in the debate over term limits for members of Congress:

It is possible for a politician at the pinnacle of power to relinquish office willingly.

Sen. Mitchell’s departure from the Senate after 15 years does not signal a trend. Others, such as Sen. Warren Rudman, R-N.H., recently have left while still in their political prime. It does, however, confirm that some elected officials mean it when they say they do not intend to make a lifetime career of holding a single office.

In this sense, his willingness to consider other challenges, while good for him, personally, also will be healthy for politics. He made his contribution, and he is leaving.

Change and turnover are good for the system.

Early in his Friday statement, the senator observed that his departure would “give someone else a chance to serve.” A veteran with a large staff of savvy insiders, he must have anticipated the dramatic ripple effect of his announcement, but the impact of his decision startled the public.

Like a reset breaker in an electrical panel, the senator stepped aside and sent a sudden surge of political energy through the Maine electoral system — right down to the grass roots in both parties.

The state’s incumbent House members, Rep. Olympia Snowe and Rep. Tom Andrews, quickly confirmed invitations to seek membership in the world’s most exclusive club.

A week after the announcement, the lists of interested politicians — Democrat and Republican — for the state’s two House seats still are fluid as tentative candidates sound out friends and advisers: “Do you think I have a chance?”

Men and women who had not considered a run for the state Legislature suddenly see opportunity, and challenge.

Many of these people, encouraged by the senator’s example of service, will seize it. A few who will remember his announcement last week to step down for his own good and that of the system, will be emboldened when they sense it is their time to let go of political power.