Ronald Reagan survived an unprecedented large crossover of Democratic voters into Wisconsin's Republican primary today and moved closer to the GOP presidential nomination with a landslide victory in Kansas.

The former California governor's Wisconsin victory dealt a serious blow to the presidential hopes of Rep. John B. Anderson, the Republican apostle of "new politics" who had tried to build a coalition of independents, disillusioned Democrats and liberal Republicans here.

In both states, Anderson battled former Central Intelligence Agency director George Bush for second place.

Reagan, arriving home in Los Angeles after a day of campaigning in Louisiana, was greeted at the airport by aides who told him of his twin victories. He said the news "delighted" him, but, as he has consistently, he declined to say that he had any stranglehold on the nomination.

"I'm, not going to decide, because I'm ahead at halftime, that the ball game's over," Reagan said.

Asked whether Bush and Anderson should drop out of the race, Reagan said that was their decision and he was not going to pressure them to do anything.

With 87 percent of the Wisconsin vote counted, Reagan had 40 percent, Bush 31 percent and Anderson 28 percent.

In Kansas, with 99 percent of the precincts reporting, Reagan had 63 percent, Anderson 18 percent, and Bush 13 percent.

In a dramatic reversal of past patterns, three of every five Wisconsin voters cast ballots in the GOP primary. Four years ago, 54 percent of the state's 1.3 million ballots were cast on the Democratic side.

Anderson was capturing 44 percent of the Democratic crossover vote compared to 31 percent for Bush and 23 percent for Reagan. And Anderson was the beneficiary of two-thirds of the liberal vote, according to an Abc News poll.

Among independents, Anderson ran almost neck-and-neck with Reagan, who made a strong pitch for bipartisan support from conservatives, and lost to Reagan by a 2-to-1 ratio among Republicans.

According to network exit polls, Reagan ran strong in Wisconsin's small cities, rural areas and suburbs, and among Slavic groups. He beat Anderson and Bush by almost 2 to 4 among blue-collar workers, and he collected about 50 percent of the conservative vote to one-third for Bush. Anderson got 17 percent.

The large crossover was attributed to the greater intensity of the GOP race and dissatisfaction with the choices on the Democratic ballot. Those who voted in the GOP primary said inflation, government spending and foreign policy were their top concerns -- problems the Carter administration has had troubles dealing with.

"I've always voted Democratic before. But this time I pulled the Republican lever for the first time," said Ted Zimowicz at a polling place west of downtown Milwaukee. "I felt funny doing it. But I had to. Carter has been a disaster. Our foreign policy is going down the tubes.

"I voted for Reagan," Zimowicz, 49, added. "As a Catholic, I couldn't vote for a baby murderer, and he was the strongest against abortion."

Jerry Knudsen, an insurance inspector who said he voted for George McGovern in 1972 and Jimmy Carter in 1976, was another crossover voter. "Carter is too wishy-washy," he said. "I'm just sick about those hostages in Iran. We need some direct action. I don't believe in this policy of doing nothing."

"I don't think Carter has been firm enough with those Iranians," said Liz Heitzman, a secretary who said she voted for Reagan. "I don't think he's firm enough on inflation. And I don't think he's firm enough with the Russians."

A total of 34 delegates to the July national convention were at stake in Wisconsin, and 32 in Kansas.

The victories were Reagan's ninth and 10th in the 13 primaries to date, and further tightened his grip on the nomination. With tonight's results, Reagan now has 395 delegates to the Republican convention, Bush 75, and Anderson, 56.

The prospect of a third-place put a further cloud over Anderson's bid and is expected to increase pressure on him to launch a third-party candidacy -- a prospect he has repeatedly hinted about during the last week.

Anderson fueled speculation about that prospect in a windy concession speech tonight. The address was more a call to arms for his "new politics" than anything else.

He said it didn't matter whether he came in second or third in Wisconsin. "There's a real sense that the competition we've been engaged in hasn't been with other candidates per se, but has been a competition of issues and ideas," he said.

"I believe it would require a new politics if we are going to emerge from the problems we have today."

For Bush, the day's results kept his candidacy alive, if just barely. They make the April 22 Pennsylvania primary, where he will meet Reagan one-on-one for the first time, all the more important.

Of Wisconsin's nine congressional districts Anderson carried only one -- the Second, which is dominated by Madison and the University of Wisconsin.

Anderson, whose Illinois congressional district abuts the state, had more to win or lose in Wisconsin than his rivals. Having yet to win a single primary, he picked Wisconsin early as one of four states to focus his attention.

"We have targeted Wisconsin as one state in which we would really like to demonstrate that there is a new coalition in America," he said repeatedly, predicting that the state's liberal cross-over voting rules would demonstrate his true strength among independents and Democrats.

Wisconsin has a tradition of voting for progressive candidates.

Anderson's stock soared here after he finished a strong second in the Vermont and Massachusetts primaries on March 4. He became the toast of the state's large university population and was picking up strong support from liberal Democrats.

"People were frustrated and they didn't know how to let their frustration be known," said Wisconsin Attorney General Bronson La Follette, a Democrat. "I heard a lot of Democrats say they were going to vote for Anderson because they didn't like Carter and Kennedy didn't have a chance."

But Anderson's support here began to fade after he finished second in his home state's primary March 18, and Kennedy's campaign revived after his upset wins in New York and Connecticut the following week.Suddenly the Illinois Republican found himself being battered from both sides.

Bush and Reagan called him "the Teddy Kennedy of the Republican Party," a candidate too liberal to become the GOP nominee. Democratic Gov. Edmund G. (Jerry) Brown of California, fearing Anderson was stealing the support of students he wanted for himself, called the Illinois Republican a conservative trying to parade as a liberal, and labeled him anti-labor and pro-nuclear power -- an unpopular campus position.

Anderson, who spent more time and more money ($456,000) in the state than any other candidate, fought back. He said he represented a "new politics" of independence and candor and hinted he might run as a third-party candidate in the fall. He directed his harshest attacks at Reagan, suggesting on election eve that the former movie actor "should go back to 'Death Valley Days' and simply imbibe some of those 20-mule team bromides."

Until last week, Reagan and Bush seemed to be looking ahead to the April 22 Pennsylvania primary, where Anderson isn't on the ballot.

Reagan, who won 44 percent of the vote against Gerald Ford in a skeletal 1976 campaign here, was so confident of victory that he spent only three days in the state. For the first time during the campaign season, he appealed for support from independents and conservative Democrats.

Bush, spirits buoyed by his much-needed win in the Connecticut primary last week, campaigned long and hard in the state. Hoping that a second-place finish would eliminate Anderson, the former CIA director tried to capitalize on a get-tough stand on the Iranian hostage situation.

A vote for Bush, a radio ad claimed, would be "the first real step toward getting our hostages home."

The Kansas primary was completely overshadowed by the Wisconsin campaign. Reagan, Bush and Anderson made only token appearances there.

Reagan was endorsed by Kansas Sen. Robert Dole, who recently dropped out of the presidential race. But he made a major snafu in a Wichita stop that angered farmers and gave editorial cartoonists across the Midwest fodder for some of the most vicious commentary of the campaign.

Asked if he supported 100 percent parity for farm products, Reagan said, "I'm not as familiar with some things as that." Full parity, traditionally a major midwestern issue, is a price for farm products maintained by federal price supports that would keep farm purchasing power at pre-World War I levels.