Washington — Although quietly jubilant over polls showing President Reagan leading Walter Mondale by a big margin nationwide, Reagan-Bush strategists are gearing up for an intensified effort in the final days of the campaign.
President Reagan will spend seven days on the hustings. He visits New York, Connecticut, and New Jersey today. On Monday he travels to West Virginia and Pennsylvania. Then, after two days in Washington, he will set out on a final tour, probably touching base in the Northeast and the Midwest before ending up in California to vote on Nov. 6.
While Reagan concentrates primarily on the states that are the most important to his reelection, Vice-President George Bush will spend the rest of his time campaigning in states where Republicans running for the US House and Senate need help.
Some 600,000 Republican volunteers will be used across the country and $19 million spent to help get out the vote on election day. Campaign officials say they have registered 4 million new voters, including more than 700,000 each in the key states of Texas and California.
A massive news media blitz is in place. The Reagan campaign says it has ''out-bought'' the Mondale campaign in every major media market and will dominate the airwaves in the remaining days.
Republican officials are elated over their party's organizational efforts this year in terms of registering voters, raising funds, and reaching out to Roman Catholics, Hispanics, Jews, and other special groups. Reagan-Bush campaign director Edward J. Rollins describes this as ''the most extensive grass-roots campaign'' in party history and forecasts that it will leave a ''lasting legacy.''
Because the Democrats also have a registration drive - they claim 5 million new voters - it is not clear what impact the new registration will have in the election. Mr. Rollins says the GOP, unlike the Democrats, has specific and accurate lists. The Republicans may also benefit from the concerted effort of the religious right to register more than 2 million new voters with the help of some 40,000 local pastors across the country.
Election experts tend to play down the importance of a high voter turnout unless the race becomes extremely close. ''The Democrats could win if not one more voter voted, and they could lose if 100 million showed up at the polls,'' says Curtis Gans, director of the Committee for the Study of the American Electorate. ''The issues and the candidates are so much more important in deciding the outcome than increments in the vote.''
''Registration as a tactic influences the election only at the margin,'' says Mr. Gans. Moreover, he adds, the only impact is from those who are sure voters for one side or the other.
The Democrats, he points out, can expect to pick up the majority of support among new black and Hispanic voters. The Republicans, in turn, will pick up most of the votes of new registrants among religious fundamentalists. But how new voters among other groups, including blue-collar constituencies, will mark their ballots is not that predictable.
In the South, even though the Republicans will not exceed the Democrats in new registrants, many new Democratic voters will vote for Reagan. ''The registration advantage to the Republicans in the South is probably at least equal to what the Democrats have done, says Gans.
According to Republican campaign polls, the President has a 20-point lead over Mondale, but Reagan-Bush campaign planners are leaving no stone unturned. On election day, volunteers will make some 15 million telephone calls to prospective new voters in 29 states. Also, some 3,000 lawyers will be working to make sure there is no vote fraud, campaign officials say.
In addition to the reelection of Reagan, the GOP expects to pick up 10 to 15 seats in the House of Representatives and either hold its own or gain a couple of seats in the Senate.
Through their intensive voter registration drive, the Republicans hope to solidify GOP support for future elections, especially in the South. Rollins notes that voter lists were not drawn up in 1976 and '80 and that the new lists, if kept up, can provide a good campaign tool for 1988.
Political experts see signs that the Republicans, while still in the minority , are beginning to gain on the Democrats, especially among young people and ethnic groups. Rollins says 31 percent of voters today identify with the GOP and 43 percent with the Democratic Party.