While the summer heat is still with us, interest in next year's United States presidential election is running way behind a cold glass of lemonade. Sooner or later everyone will have to get out of his hammock, but meanwhile politicos continue to flounder around in a pretense of excitement.
No one knows for sure whether John Glenn is the front runner for the Democratic presidential nomination and Walter Mondale second, or vice versa. And while the lemonade pitcher is still half full, no one seems to care.
Whichever way it is, Sen. Alan Cranston figures he is third and maybe creeping up slowly on whoever is second. In this particular sequence, third isn't too much different from first anyway.
On the other side is President Reagan, whose main activity is tossing pleasant exchanges to attentive news people on his way back and forth from the heli-copter.
So far, he hasn't admitted even to himself that he is running for a second term. In the hot weather, this passes for political wisdom, because it means, supposedly, the Democrats won't know whom they are running against. Except there is really nobgdy else. Mr. Reagan is the front runner on the Republican side at this point no matter what he says, or does.
What does this leave for excitement? Well, there is the ritualistic guessing game as to when, if ever, President Reagan will make his surprise an-nouncement.
Our best guess is that it will be when he makes a triumphant return from a China trip in mid-November. This kind of announcement is always made at a high point in the presidential term, so right now coming back from China looks like the highest point in a political landscape which makes Indiana look like Switzerland.
China has long been a sure-fire place for politicians, news people, travel agents, and conservative presidents to return from. In China there are no screaming protesters, no egg throwing, no shouts of ''Reagan go home.'' So as long as one can drink the water and eat egg foo yong he has made a success of it.
Anyway, the Oriental has a fascination for Americans. As long as Americans continue to dote on tasteless Chinese fortune cookies, no further reason is necessary for American presidents to select China as the country from which to make triumphant returns.
There will be a span of about 24 hours in which the announcement can be made before some rude American remarks set the record straight.