If Custer could return to the Little Big Horn, he might feel a little bit like George Bush did today coming back for the first time to the city and state that hosted his most embarrassing -- and his fatal -- primary encounter with Ronald Reagan.

It was in New Hampshire that Bush's "Big Mo" [momentum] presidential campaign first took a nosedive, starting with a one-on-one debate with Reagan in Nashua. The debate turned into a humiliation for Bush three days before the New Hampshire primary when Reagan, in a brilliant political move, invited all the Republican candidates onto the stage.

There a befuddled Bush watched an indignant Reagan shout to the moderator, "I paid for this microphone!" as the other Republican candidates stood outraged on the stage.

Bush would probably rather forget the Nashua debate. But on his return trip today, he had plenty of reminders.

First, at the Manchester airport, reporters questioned Bush repeatedly as to whether, if not for his Nashua Waterloo, he would have gone on to win the GOP nomination, instead of the No. 2 spot to presidential nominee Reagan.

"All I know is, that's history," Bush said. "I don't like rehashing old wounds. The common ground transcends the divisions of the primary."

But Bush was not quite through with the topic of debates. The issue on the minds of reporters at every stop was whether he would accept an offer from the League of Women Voters to appear on a podium with Vice President Mondale and Patrick J. Lucey, running mate of independent presidential candidate John B. Anderson.

Bush ruled out any debate on Oct. 2, as the league had planned, claiming scheduling conflicts. Bush said he had no hesitation about "debating two Democrats," but called the vice presidential debate secondary to the on-again, off-again presidential debates that now seem off again. Bush referred to the vice presidential debates as "the Toledo Mud Hens -- it's just not the big leagues."

Then, as Bush's Leadership 80 jet lifted its wheels out of New Hampshire's Manchester airport, Bush was given one last reminder of that embarrassing Nashua debate with Reagan Feb. 23. Members of Bush's traveling press corps presented him with a silver Highball microphone, engraved with the words, "We paid for this microphone."