THROUGH REPUBLICAN votes have been counted in only six contests -- Iowa, Puerto Rico, New Hampshire, Massachusetts, Vermont and South Carolina -- more than half of the original presidential contenders either have been counted out or have counted themselves out. Shortly after the dimensions of Ronald Reagan's South Carolina victory became apparent, John Conally withdrew from the campaign with this observation: "Ronald Reagan is still the champ and we just didn't overtake the champ."

Certainly, beginning with his big victory in New Hampshire, Mr. Reagan has been on the move. With the prospect of victories in Florida, Alabama and Georgia today, his campaign could become a band-wagon heading into Illinois and New York. In 1976, when he came within 50 delegates votes of upsetting then-president Gerald Ford at the Kansas City convention, Mr. Reagan did not win his first primary until March 24. That victory, in North Carolina, came after Mr. Ford had won Iowa, New Hampshire, Massachusetts, Vermont, Florida and Illinois. This time, Mr. Reagan is running far ahead of his earlier pace and is not carrying the baggage of challenging a president of his own minority party.

Still in the race are George Bush and John Anderson. Rep. Anderson ran ahead of Mr. Reagan in Massachusetts and Mr. Bush in New Hampshire, but he has yet to win any Republican contest. He is not even campaigning in the southern primaries and is betting his growing bankroll and limited hopes on Illinois and Wisconsin.

Mr. Bush's Iowa victory won for him the public spotlight, but victories in Puerto Rico and Massachusetts did not take the sting out of his one-sided defeat in New Hampshire. But Mr. Bush, in direct contrast to the Reagan campaign, has rationed his resources more shrewdly than the other Republican candidates and, as of now, is best positioned logistically for a long haul.

But logistics don't get counted; votes do. So George Bush has to beat the front-running Ronald Reagan somewhere, and fairly soon. If he cannot, the "pressure" (much of it seemingly self-generated) on Mr. Ford to enter the contest will grow. The most recent Harris poll, which shows that Mr. Ford would defeat President Carter as of now, will increase the likelihood of Mr. Ford's entering the race -- much to the consternation of Mr. Bush and Mr. Anderson and much to the advantage of Mr. Reagan. While there is still a long way to go, we find ourselves in basic agreement with John Conally: the Republican contest is becoming Mr. Reagan's to lose.