Reagan runs

President Reagan returns to the campaign trail for reelection with a number of achievements to run on. His leadership style, the vigor of his actions, and the tenacity of his views have enabled him to set the Washington agenda to a degree not seen since the mid-1960s, when the decline in the public's confidence in its leaders began.

President Gerald Ford had brought a healing sense of goodwill back to a Washington embittered and saddened by Watergate. Given a little more time in the campaign, he might have been reelected. Jimmy Carter proved that someone from the Deep South could become president, which helped put behind old regional grievances. But he showed an intensity, a relentless grindstone quality, that was unfortunately not matched by effectiveness. Carter's most singular achievement, the Camp David accords, was offset in the public view when Congress ignored him outright on energy and SALT II, and when Iran strung out the hostage drama.

Mr. Reagan has looked comfortable with himself and the office. This was welcome to Americans, who don't like to see their top executive burdened by the job. Reagan's buoyancy after the early assassination attempt won him wide respect. In his holding off pressures from inside his own camp, as well as from without, on a range of issues from his initial tax-cut plan to his posture toward Soviet expansionism, he has clearly shown he makes his own decisions.

Reagan has also made his brand of cabinet government work for him in Washington. He delegates the development of budgets and programs that are remarkably consistent with the policy blueprint laid out in his 1980 election campaign. His White House staff has slipped at times, notably in its early handling of social security. But the larger impression is that, despite its own divisions, his staff has ably represented the President on Capitol Hill and in negotiation with domestic power blocs. Particularly in domestic affairs, Reagan's has been a well-coordinated presidency.

Politically, the melding of the Ford-moderate and Reagan-conservative wings of the party under Reagan's leadership has worked rather well. Reagan signaled his wish to get on with the moderates by considering Gerald Ford as a running mate, and then accepting George Bush as his vice-president. Some of the ablest talents of the two wings were brought into the 1980 campaign and into the White House. They are working again in tandem for his 1984 campaign. When one considers the harsh intraparty GOP fights of recent decades, Reagan's achievement in securing a relative truce should be acknowledged.

Then there's the recovery, the low rate of inflation, and declining unemployment. The whys and whithers of current economic trends will be debated during the campaign. But at the outset of the official GOP entry, his claim that ''America is back'' finds many Americans nodding in agreement about domestic confidence.

Abroad, Mr. Reagan's own people express reservations about the immediate returns from his more assertive, force-based diplomacy. They look to a second term to show results. They argue that a stronger America is a safer America. The Democrats already emphasize what they call resurgent war fears about Reagan. The administration counters that it is willing at any time to negotiate with adversaries, but from a position of strength. Inclusion of a 14 percent defense spending increase in the fiscal 1985 budget shows the President remains committed to a militarily more powerful America.

To the degree he has fulfilled a major portion of his 1980 pledges - to reverse federal spending priorities from social programs to defense, to fight regulation, to use the presidential bully pulpit to highlight issues like school prayer and abortion - Mr. Reagan has clearly earned the right to seek his party's nomination again.

And George Bush - on the basis of loyalty, hard work, familiarity with his chief's policies and programs, his own prior government experience, and qualification to take over - makes sense again on the ticket.

Reagan's announcement brings a certitude about the American election that was lacking before. The Soviets must now think back over their negotiating strategy. The Democrats' opposition is now clearly defined. Republican troops across the nation have had their election juices primed. The contest has been officially joined.