The race for the Republican presidential nomination has narrowed to three after Monday's Iowa caucus, according to Harvard political observers.

The top three finishers in Iowa, U.S. Sen. Robert J. Dole (R-Kan.), conservative columnist Patrick J. Buchanan and former Tennessee Gov. Lamar Alexander, are now the front-runners for the nomination as the presidential campaign swings east for Tuesday's New Hampshire primary.

In Monday's caucus, Dole won 26 percent of the precincts, Buchanan surprised observers by winning 23 percent and finishing second, and Alexander rounded out the top three with 18 percent.

"Alexander, Dole and Buchanan got the three tickets out of Iowa," said IBM Professor of Business and Government Roger B. Porter, a former aide to Presidents Reagan and Bush.

But experts said close margins give no single candidate a superior lead going into New Hampshire. The three in the Granite State must also contend with the upstart and well-financed candidacy of millionaire publisher Malcolm S. "Steve" Forbes Jr.

"The race is far more open than anyone thought a month ago," said Visiting Professor of Government James W. Ceaser, a presidential expert from the University of Virginia. "Dole did not have a very impressive victory."

However, Porter said he thinks Dole still has a good shot at the Republican nomination.

"In politics, winning counts," he said. "Finishing first means you finished first."

Yet before Dole can claim the nomination, he must defeat a rejuvenated Buchanan, and he must combat the moderate candidacy of Alexander.

Buchanan, whose second-place finish in Iowa followed his stunning victory in Louisiana earlier this month, was successful because he capitalized on the large Christian right following in Iowa, Ceasar said.

He said support from "social conservatives," an estimated 39 percent of Republicans, boosted Buchanan to his high finish.

"The religious right is an enduring constituency," he explained.

But Ceaser said Buchanan's chances at defeating Clinton in November are slim, because the religious right is not a broad enough base of support for a presidential candidate.

The other Republican candidates, U.S. Sen. Richard G. Lugar (R-Ind.), U.S. Sen. Phil Gramm (R-Tex.), U.S. Rep. Robert K. Dornan (R-Calif.) and commentator Alan Keyes '72, no longer have a chance to make a serious bid for the nomination, Ceaser said.

Porter said even Forbes, who campaigned hard in Iowa and has bought a plethora of ads on New Hampshire television, will have trouble winning the Granite State.

"The number of expenditures on advertising can only take you so far," said Porter.

Yet as the candidates now make the trek east, the race is far from over.

Porter pointed to Reagan and Bush, both of whom lost the Iowa caucus and went on to win the final nomination.

"New Hampshire is going to be a new ball game," Porter said