WASHINGTON – Now that Hillary Clinton has finally declared her presidential candidacy for 2016, the country can look forward to another interminable stretch of pre-election shadow boxing, until the first voting in the Iowa caucuses early next year.

The lineup of contestants for the slog is a curious one. In the Republican Party, 20 or more aspirants have already burst out of the starting gate in a number of meaningless trial heats and straw polls.

An army of print, radio, television and Internet analysts is already reading the skimpy tea leaves to discern who’s ahead and who’s behind.

By contrast, in the Democratic Party, only Hillary Clinton so far is out on the track, with financial and womanpower support already lined up, scaring off all but the most ambitious or self-delusional challengers willing to test her.

The Republican wannabes each have a reasonable chance that the prize may well come their way. The most experienced of them, former Florida Gov. Jeb Bush, is haunted mainly by the past of his brother George’s two bollixed wars.

So voters will be treated over the summer, fall and early winter to the dismal prospect of unenlightening political back-biting.

The GOP pack will continue for a while piling on President Obama and Hillary Clinton before turning to the predicable internal cannibalism that will follow, as the winnowing-out process proceeds in Republican debates.

Meanwhile, Hillary will continue on her strategy of selling herself as a low-profile best friend to Democratic voters, as she remains the only show in town on her side of the partisan divide. The few Democrats who choose to enter the fray may do so principally to keep her honest on issues dearest to the hearts of the liberal faithful, such as the yearning for a less interventional foreign policy.

None of this outlook augurs a particularly exciting or constructive period ahead for the country, nor for Obama, as the nation struggles through the 20 remaining months of his lame-duck presidency.

A positive Obama legacy is in doubt in spite of his best efforts to achieve economic recovery from the Great Recession he inherited. And the jury is still out on his prime objective of ending the two wars bequeathed him by his Republican predecessor.

That challenge alone will limit the political help Obama will be able to give his former secretary of state as she vies for the Democratic nomination, or for her election if all goes well for her at the party convention.

The Republican hopefuls will see to it that her State Department tenure will be cast in the worst possible light, with her handling of the Benghazi controversy kept smoldering.

In light of this, a good argument could be made for returning to the ways of earlier times when prospective presidential candidates withheld their ambitions and there was none of the outrageous fund-raising, fat-cat super PACs and nonstop campaigning that marks so much of today’s presidential election cycle.

It’s almost enough to make one yearn for the first days of the Republic, when presidential candidates, including incumbents, didn’t overtly campaign for the highest office at all.

Traditionally they stayed home and left to others the business of hustling votes. For a time, the most an incumbent would do to hold onto the Oval Office was to entertain callers on his front porch in the fashion of William McKinley back home in Ohio.

That extreme, of course, is neither practical nor desirable today. Voters want and need to have presidential candidates reveal their objectives and intentions, and the public is served by an aggressive press corps seeking the information on which responsible voting can be based.

But the whole exercise of running for president, particularly how much it costs and who pays, has gotten out of hand.

It’s literally the case that no sooner has one election been decided than the next one gets underway, wearying and exhausting all concerned. Enough already.

Editor’s note: Jules Witcover’s latest book is “The American Vice Presidency: From Irrelevance to Power,” published by Smithsonian Books. You can respond to this column at juleswitcover@comcast.net.)