With Bob Dole poised to claim a commanding majority in Tuesday's seven-state primaries and secure his lock on the Re-pub-li-can presidential nomination, his nearly crippled challengers face mounting pressure to surrender.

But all signs showed Pat Buchanan and Steve Forbes digging in for a long fight, even as polls in the "Super Tuesday" states put them at long odds for winning many - if any - of the 362 convention delegates at stake."We're going all the way to San Diego. That decision has been made. That issue is closed," Buchanan said Monday night, referring to this summer's Republican national nominating convention.

Forbes said from Florida, "I'm in for the duration."

Despite the pair's insistence, several Republican heavyweights backing Dole, including House Speaker Newt Gingrich, lined up Monday to try to push them from the race.

"The longer Pat campaigns, the less effect he's going to have. He's made his point. People understand his message. Now it's time to be part of the team," Gingrich said in Atlanta.

But Indiana Sen. Dick Lugar, who dropped out of the race a week ago and endorsed Dole, said Tuesday he believes that Republicans in the end will unite behind the nominee no matter how contentious the primary.

"The question now is . . . to try and unify the party before San Diego," Lugar said on "Fox Morning News." "I think you simply rally round the obvious winner, Bob Dole. And I think Republicans will do that. Not all will lay down their swords for the moment. But at the same time I think we're headed to remarkable unity by San Diego."

Still, with Dole's nomination all but mathematically assured by his delegate count,questions over whether or when the duo would quit provided the only drama on the eve of the balloting.

Each of the states was also holding a Democratic primary, but President Clinton faced no serious opposition.

Going into Tuesday's contests, Dole had amassed 392 delegates, more than a third of the 996 needed to clinch the nomination. Forbes had 73 and Buchanan 62.

"In my view I am the front-runner," Dole said, while campaigning in Fort Lauderdale, Fla. "I think I will get the nomination."

He left it to surrogates to nudge challengers out of the way. "I've never been very good at putting pressure on people. There will come a time when someone needs to reach out to both of the remaining candidates," Dole said.

Buchanan on Monday declined to rule out the possibility of a third-party run.