Simon and Robertson all but out. TWILIGHT CANDIDACIES

Democratic Sen. Paul Simon and Republican Pat Robertson will no longer take to the hustings in their respective quests for the White House, but neither candidate plans to withdraw completely from the presidential race. Senator Simon wants to hold onto his approximately 180 delegates until the Democratic National Convention in July. And Mr. Robertson wants to keep his name in circulation in GOP circles. Consequently, each man has suspended active campaigning, but neither has officially thrown in the towel.

``I have no illusions that the nomination will come my way,'' Mr. Simon said at a press conference yesterday. But that doesn't mean he wants to lose his influence. One aide said Simon might want to push for a particular vice-presidential candidate, such as Arkansas Sen. Dale Bumpers, a personal favorite.

``If there is a deadlock at the convention, Paul wants to be a part of that,'' says Bob Edgar, Simon's former finance director.

Simon's press secretary, Terry Michael, adds, ``To have a voice in this process - to help nominate the most electable candidate - it is helpful to have delegates.''

Simon must also be concerned about his reelection to his Senate seat in 1990. Some Illinois political analysts think he may have strayed too far to the left while on the campaign trail, and that he needs to build support in the state to improve his position.

There was speculation after he put his campaign on hold for the Super Tuesday contests that the only reason he was staying in at all was to pave the way to the Democratic convention for his Illinois supporters. By not formally dropping out despite his poor showings in recent contests, Simon ensures that his people will be in Atlanta in July.

``A number of those delegates are very important people to Paul Simon, and he wants them to be major players in the selection of the next president,'' Mr. Edgar says. ``To simply walk away and give up a sizable number of delegates that he has would jeopardize, to some degree, his relationship with those folks.''

Simon's decision to become an inactive candidate is without precedent. It allows the people elected to fill the delegate slots he won in Iowa, New Hampshire, and Illinois to continue on to the convention. It also means that the at-large delegate slots that these states have allotted to Simon (in proportion to his primary or caucus results) will remain locked in.

If Simon withdrew from the race altogether, as Rep. Richard Gephardt did last month, his at-large delegates would go to other candidates. In the case of Illinois, for instance, the 47 at-large delegates Simon won by finishing first in the state caucuses on March 15 would be reallocated to the Rev. Jesse Jackson, who was second in that contest.

``We far surpassed the conventional wisdom about what Paul Simon could do in this race,'' Mr. Michael says. ``[Simon] was at 1 percent in the first Des Moines Register poll. People laughed at his candidacy ... and then in November we found ourselves in first place in Iowa. We just weren't able to sustain it because of some bad breaks.''

Pat Robertson announced Wednesday that he will end active campaigning.

``We expect Bush to get the nomination, but we're not withdrawing,'' said Marc Nuttle, formerly Mr. Robertson's campaign manager and currently a political consultant to the former television evangelist. ``It's just not going to be at the pace that it was.''

To keep his name in the public eye, Robertson plans to accept invitations to speak before large organizations, rather than put together his own rallies. He has yet to endorse Vice-President George Bush, but he plans to do so before the Republican National Convention in August. Mr. Nuttle says Robertson is committed to party unity and will work hard to keep his supporters, many of them former Democrats, in the Republican fold.

``We're certainly doing everything we can to keep them in, and I think as long as they focus on the party platforms of the two parties, the only choice they have is the Republican Party,'' Nuttle says.

Robertson will maintain enough of a staff to keep his state organizations intact. He now exercises partial or complete control of the Republican machinery in about 20 states, according to Nuttle, and they are determined to maintain their influence. The campaign will refocus to a ``convention mode,'' with efforts to train Robertson backers and get them to New Orleans in August.

``He's learned a lot about everything from the party and how it works to the press and how they accept ideas,'' Nuttle says. ``He'll be better in the future.''

Robertson has stated his intentions to run again. Says Nuttle: ``[Robertson] plans to be a lifelong Republican and to help build the party to majority status, which would include 1992.''