Each time presidential candidate Alan Cranston travels to Chicago, he insists upon being booked into the Airport Hilton. The reason: The corridors there are exactly 250 meters (275 yards) long - just right for him to do his regular, early-morning wind sprints.
That's more than campaign hyperbole for the liberal California senator. He once held the world record for the 100-yard dash (12.6 seconds) for people over 55. He still competes in 60- and 100-meter races. And he is Capitol Hill's acknowledged speed-bicycle champion.
All this is relevant because Senator Cranston will be 70 next June, and would be the oldest person ever to win the presidency. His campaign for the White House has battled charges that he is not only ''too old,'' but also ''too liberal'' and ''too dependent on a single issue'' (the nuclear freeze).
In fact, many of the experts laughed when Cranston got into the 1984 race. But the senator, working seven days a week for months at a time, has raced from Massachusetts to Iowa to Wisconsin to New Hampshire in search of support. And he has done much better than expected - moving for a time into third place in the national polls behind Walter F. Mondale and John Glenn.
From the beginning, Cranston has waged a high-risk campaign. After all, he started far, far behind - in terms of money, name recognition, organization, and support among Democratic Party activists across the nation.
His almost exclusive reliance on the freeze issue - he later added the issue of full employment - risked making his appeal too narrow. He also risked every bit of the campaign cash and manpower he had to make good showings in nonbinding straw polls in several states in an effort to gain credibility.
To an extent he succeeded. He ran away from Reubin Askew, Ernest F. Hollings , and fellow liberal Gary Hart in the polls. But in the last few months, he has found it difficult to broaden his appeal beyond a narrow base, and has watched himself fall further and further behind the leaders.
The late entries of George McGovern, the most liberal candidate of all, and black civil rights leader Jesse L. Jackson have also hurt, for they have drawn from Cranston's natural constituencies. As a result he has watched himself slip from a solid third-place standing this summer to a weak fifth (with only 2 percent support among Democrats) in the most recent ABC/Washington Post poll.
Even in his native California, Cranston has dropped behind the front-running Mondale in the most recent statewide survey by pollster Mervin D. Field.
So is the campaign over for Cranston?
Perhaps not yet. He still has two factors working for him - the candidacy of John Glenn, and his own campaign organization.
From the beginning, Senator Glenn has been a big part of the Cranston strategy. Glenn represents the middle ground of the Democratic Party. He's someone who can appeal not only to party regulars, but also to independent voters and dissatisfied Republicans.
When Glenn and Mondale finally butt heads in Maine, Iowa, and New Hampshire, and in the 10 primaries and caucuses on ''Super Tuesday'' (March 13), Glenn may surprise the experts and deal Mondale a devastating blow. If he does, Mondale's standing ''could sink very quickly,'' suggests a Cranston aide. And if that happens, Cranston will be there ready to take up the liberal mantle.
''Front-runners have fallen by the wayside before,'' a Cranston strategist observes.
Cranston also has something else working for him - his organization. Some of the other candidates have expressed surprise that he would put so much work into straw ballots among Democrats in Wisconsin, Maine, Iowa, and elsewhere. Straw polls, after all, don't elect delegates. And they have drained the Cranston campaign of badly needed funds.
But Cranston aides look at it another way. Many of the delegates to the 1984 Democratic convention will be elected in caucuses beginning with Maine and Iowa in February, and then New Hampshire. Winning support in caucuses is very much like winning votes in straw polls. Instead of ducking the straw polls, as Glenn has done, the Cranston team went all out. And they have gained valuable experience and important contacts in doing so. Now when the caucuses begin, they will have people on the staff who know how to produce the votes for their man.
Cranston, in fact, has proved himself to be a solid vote getter through most of his political career. He is the only Democrat ever to win a third term to the US Senate in California. He received 4,705,399 votes in his 1980 reelection, more votes than any candidate for the US Senate has ever received in any state. (California, of course, is the most populous state.) And his 1980 vote was nearly 200,000 more than Ronald Reagan received in California that same year in his presidential race.
Political-watchers in California say there are no secrets to Cranston's great popularity in the Golden State. It's mostly just a matter of good, old-fashioned politics.
Cranston is probably more liberal than the typical California voter. But most people don't seem to mind, because Cranston votes right on issues that affect the state directly.
An example: the B-1 bomber. Cranston, a champion of the nuclear freeze, nevertheless supports the B-1. The senator explains that he believes in the deterrent value of the US triad (bombers, land-based missiles, and submarine-based missiles), and that the present Americanbombers, the B-52s, are getting very, very old. But it is also true that California workers are highly dependent on the aerospace industry, and the B-1 will create millions of dollars' worth of jobs there.
California pollster Field points out that statewide leaders usually do well if they manage to ''stay out of trouble'' and avoid bad publicity. Cranston certainly has. He has a solid image as a hardworking minority whip in the Senate , and his approval rating in California has remained very high.
Meanwhile, he continues to hammer away at his themes. He charges that Mondale is promising something for everyone, vowing to do ''everything from A to Z.'' It can't be done in four years, notes Cranston, who adds that he is promising only to do ''A and B.''
''A,'' of course, is reduce the threat of nuclear war. The growing concern in the country, says Cranston, is that President Reagan is ''too quick'' to use force ''to deal with complex international problems.'' Cranston consultant Mike Rowan says the public doesn't see that as a ''single issue,'' but rather as the ''singular issue'' of our times.
Cranston plans to center a fund-raising effort on the television movie ''The Day After.'' airing this Sunday on ABC. The ABC program dramatizes the aftermath of a nuclear attack on Kansas City.
''B'' is to back economic policies that will put the country onto a better economic footing. In particular, Cranston says he would: lower the federal deficit, which would reduce interest rates; support monetary policies that would also bring down interest rates; and develop an industrial policy that stresses the human element, with job training and a national development bank to help the central cities.
Cranston may not win the nomination, but he plans to make a fight of it - with his campaign rejuvenated with federal matching funds Jan. 1. If the campaign seems high-risk to others, so be it. Cranston aides note that he has fought such battles before.
There was, for instance, the time he battled Adolf Hitler. It happened in 1939. Cranston, then a young journalist, had produced an unauthorized, 10 -cent-a-copy edition of Hitler's ''Mein Kampf,'' complete with lots of anti-Nazi footnotes. Hitler's agents sued, and Cranston was forced to pull his book off US newsstands. But Cranston always felt his effort had been a moral victory. Before Hitler won the injunction, Cranston had sold 500,000 copies of his anti-Nazi version in just 10 days.