Republican pollster Richard B. Wirthlin contends that President Reagan's disapproval rating has increased because the president is "using his political honeymoon" to translate his budget-cutting campaign promises into practice.

Wirthlin said a poll he concluded last week for the Republican National Committee shows that Reagan's disapproval rate, which he did not specify, rose because of opposition to some of the proposed budget cuts.

"We are seeing a pattern very similar to the one we observed when Ronald Reagan became governor of California," Wirthlin said in an interview. "In California, as now, he attempted to immediately implement his campaign promises. This coalesces support and polarizes opposition."

What it means, said Wirthlin, is that Reagan reaches his basic level of opposition in a hurry and maintains it. In this context, he added, the support of more than 60 percent of the people which the president now enjoys is "a very strong sign of approval."

At the same time, Wirthlin disputed the findings of the Gallup Poll, which showed Reagan approved by 59 percent of the people and disapproved by 24 percent after two months in office. Wirthlin said his own poll showed "a substantially lower disapproval rating," a figure he described as "in the high teens."

One possible difference in the Gallup and Wirthlin findings is that Gallup gives Reagan only a 57 percent approval rating in the West, traditionally his strongest region in polls or elections. Wirthlin, with a considerably large sample, gives Reagan 70 percent there.

Within the Reagan pollster in the 1980 presidential campaign, now has moves the executive headquarters of his polling firm, Decision Making Information, from California to Washington and is polling regularly on voter attitudes under contract with the RNC.

In another evaluation, a leading Democratic pollster discounted what he called "a rush to judgment" on how Reagan is doing.

Peter Hart, who polled for Sen. Edward M. Kennedy (D-Mass.) in the 1980 campaign, said that the poll findings so far are "inconsequential" and that it doesn't make much sense to compare Reagan's performance after two months with that of other presidents.

"Presidents' first months aren't the same, and it's not terribly helpful to compare them," Hart said. "The times are different for Roosevelt, for Eisenhower, for Reagan.

"We're in the prologue of a five-act drama, and we really won't know how Ronald Reagan stands with the public until he faces his first major test. There's always a rush to judgment by media and politicians, but I though we had learned from 1980 that we weren't going to trust the polls anymore."

Although Hart does not use the approval yardstick in his polls, he basically accepts the accuracy of Gallup's findings. He said it is not surprising that Reagan's disapproval rating is higher than Jimmy Carter's was at a similar point.

"Reagan has basically made a career of polarizing people, so he came into office with a constituency of people opposing him," Hart said.

As Wirthlin sees it, this opposing constitutency was further rallied by the president's budget-cutting, producing significant levels of disapproval in the East and among minority groups, especially blacks.

Perhaps Wirthlin's most interesting finding was that the percentage of Americans who identify themselves as "Republican" has steadily increased since the election. This has prompted Wirthlin to alter his post-election view about whether last November's was a "realigning election" in which voters actually change basic party allegiance.

Wirthlin's latest figures show 42 percent of voters identifying themselves as Democrats, 34 percent as Republicans and 25 percent as independents. A year ago Democrats hd a 20 percentage point lead over Republicans.

It is generally accepted that the last major political realignment in the United States took place from 1932 to 1934, the first years of the New Deal. Led by Franklin Delano Roosevelt, Democrats became the majority party, a position they have maintained until the present day. But scientific public opinion polling was then in its infancy.