A STRANGER in Washington last week easily might have imagined that the next presidential election campaign was only months away or that the congressional races lay 17 weeks -- not 17 months -- ahead. Signs of renewed interest in both past and future campaigning could be found throughout political Washington.

First came the Maryland media blitz against Democratic Sen. Paul Sarbanes a few weeks ago by the National Conservative Political Action Committee's negative nabobs, a classic cut-and-thrust warmup designed to stir controversy about Mr. Sarbanes by reiterating in prime time the ominous, if obvious, point that he is -- get this -- not a conservative Republican. Not to be outdone, some of Mr. Sarbanes' Democratic supporters in a newly organized PAC called "Democrats for the '80s" counterpunched last week with advertisements of their own designed to prove that NCPAC fights dirty.

For a time, the conservative group also found itself pummeled from within Republican ranks. The party's national chairman, Richard Richards, attacked independent campaign spending groups such as NCPAC for irresponsibility and for creating "all kinds of mischief." Mr. Richards' statement, in turn, provoked the White House's political strategist, Lyn Nofziger, to a public defense of NCPAC and similar groups that level attacks on Democrats. At that point, Mr. Richards found himself in uncomfortable public harness not with his own administration but with his Democratic counterpart, National Chairman Charles T. Manatt, who denounced the conservative fund-raising groups and named Theodore Sorenson to lead a committee inquiring into PACs. (Mr. Richards countered with the inevitable appointment of a Republican "study group" to examine all problems of election law reform.) the week's chain of criticism concluded with Mr. Manatt himself coming under attack by some Democrats for proposing an eminently sensible change in party arrangements to restore its officeholders to positions of party influence.

Meanwhile, back on Capital Hill, the Senate Rules Committee received messages from ex-presidents Nixon, Ford and Carter supporting discussion of a proposal to hold the quadrennial presidential election on a Sunday and to prevent television networks from broadcasting projections of electoral winners before the polls close. Across town, in a uniquely ecumenical political pronouncement, legal counsels to the Reagan and Carter campaigns, to both Republican and Democratic campaign committees, and to seven unsuccessful 1980 candidates -- Anderson, Baker, Brown, Bush, Connally, Dole and Kennedy -- released a joint letter to the Federal Election Commission that complained about a variety of FEC sins of omission and commission in administering the election laws during the 1980 campaign. The grievances expressed both in the joint letter and in the Senate hearing on revisions of election law indicated the varieties of discontent with current campaign practices.

By anyone's measurement, therefore, after months of post-election doldrums, politics has resumed in earnest. Even the week's most dramatic political event -- the defection by 63 House Democratics to vote for the Reagan budget proposals -- while not wholly unexpected, provided additional evidence that linked the first stirrings of Campaign '82 (and '84) to unmistakable signs of party realignment.

As the Reagan administration ages and experiences the setbacks normal to governing, the reports of Democratic demise now so widespread may come to seem foolishly premature. For the moment, however, it seems apparent that, on natural political questions, conservatives and Republicans not only have "got the fever" but also have got the votes. Neither round-the-clock presidential balloting on Sunday, nor greater regulation of PACs, nor even reform of the Federal Election Commission will emerge from Congress into law unless a coalition remarkably similar to the one responsible for the president's impressive budget victory in the House bestows its bipartisan blessing on the proposal.