IT'S difficult to believe now. But only a few months ago Gary Hart seemed to be on the ropes, so much so that when reporters met with him they thought he would announce his departure from the race.
The questioning was blunt. Was he about to go ''bankrupt?'' Was he about to ''give up?''
The senator conceded that ''all these rumors about my demise'' were hurting. But he insisted that he and his campaign were still alive and well. And then in a rather tired, put-upon way the senator talked about his plight:
''We have spent six to eight weeks denying these rumors. But they persist. There's nothing you can do about that. You just go on. If you believe in yourself and the cause you represent, then others do, too. So these stories don't really matter. They are more of a nuisance than they are reality.''
After the meeting some reporters described Hart as doleful and ''down.'' One said, with others nodding agreement, ''His campaign isn't long for this world.''
That was late July of last year.
How best to explain the Hart upsurge? For one thing, he has showed most clearly he possesses the quality of ''stick-to-it-tiveness,'' a word that Teddy Roosevelt coined and himself exemplified. But beyond that, what is becoming the accepted wisdom on the so-called ''Hart phenomenon'' was well expressed recently by House majority leader James Wright.
Mr. Wright spoke of the ''distinct, romantic desire among the American people to cheer on a horse that comes from back in the pack.'' He also thinks ''there is inherent in the American character a kind of mistrust of things big - big government, big labor, big business - and somehow that onus has been attached to Walter Mondale.''
But there is another element in the rise of Hart:
The Democratic Party has had, for a generation now, a growing split within its liberal wing. There are those, mostly older Democrats, who cling to the old FDR philosophy of throwing government money at a problem if it needs fixing. And there are others, growing in numbers, from the young and middle-aged group, who are eager to find a new approach to making government work.
These younger Democrats sound somewhat like conservatives in that they want to end that big budget deficit and think it is high time to bring more efficiency in government. But their main target is achieving reductions in defense, not social programs. And they think Reagan has been insensitive to the poor and disadvantaged in his tax-cut and spending-cut program.
In any event, these liberal, or neo-conservative, Democrats, as some of them call themselves these days, are looking ahead and not back at the old, special-interest politics President Kennedy had practiced on the way to the White House. And they have found a champion in Hart with his ''new ideas.''
These liberals are enthusiastic activists who are from the same mold that produced highly effective earlier campaigns for Eugene McCarthy, Robert Kennedy, and George McGovern.
So, with zeal and vigor, these intensely involved liberals are making themselves felt far beyond their numbers in a primary and caucus process in which only a relatively few Democrats are bothering to take part.
Last July, Senator Hart said something that the reporters there didn't heed. ''There are stories,'' he said he was hearing, ''that the Mondale campaign isn't living up to expectations.''
Also, Hart said he was setting up a very strong campaign organization in New Hampshire and Massachusetts. No one listened. Hart - reporters were convinced - was on his last legs and wasn't worth listening to - at least, very much.
Clearly, Hart has risen far since those dark days. And despite Illinois, he may well still have the momentum. The New York primary will tell us much about that.
Wright sees a ''good possibility'' of a deadlocked convention. If that happens, he believes Mondale would have the advantage since most of the leaders who will be delegates there will be in the Minnesotan's camp.
Wright smiles and says there's a possibility of ''a return to the smoke-filled room,'' a reference that evokes memories of the past when influential politicos shaped the presidential ticket. He also sees the likelihood of Jesse Jackson becoming pivotal in a deadlock, with Mondale being more likely than Hart to become the beneficiary of the Jackson delegation.