Washington — Come on out and fight. That is Walter Mondale's challenge to Ronald Reagan. Yet, as the Democratic candidate doggedly tries to attack his opponent on the ''issues,'' the President is confidently conducting a campaign relying heavily on presidential image, power of incumbency, and personal popularity. He is talking about issues only in a general way, carefully avoiding getting specific about what he would do if elected to a second term.
It is a strategy that seems to be working for the President and one that leaves Democrats frustrated. They would like to make Mr. Reagan expose his future plans and bring him out of what they call his ''isolation.'' They are itching to have Mondale debate him.
But as Reagan this week heads out to the states of New York and Tennessee as part of his post-Labor Day campaigning, GOP campaign operatives say they see no reason to shift strategy - a strategy common for an incumbent as opposed to a challenger.
''Reagan will review the progress made in his first term and may flesh out his themes for a second term,'' says John Buckley, deputy spokesman of the Reagan-Bush reelection committee. ''But there is no need for him to get specific, because he stands for things, for philosophical viewpoints, and people know what he would do in a second term. The overall thrust of his administration has been set.''
''Are people looking for specifics?'' rhetorically asks Charles Black, political consultant to the Reagan campaign. ''The biggest consideration is Reagan's four-year record, and he's made more specific proposals than any president in a long time. He's pushing the same agenda.''
This suggests voters will continue to hear the President sound positions stressed on the hustings so far:
* The economy is buoyant and growing stronger.
* His defense buildup has bolstered America and made it respected again.
* He will continue to urge the Soviet Union to ''join us in keeping the peace'' and in reducing nuclear weapons.
* His leadership offers hope and a ''sparkling vision of tomorrow'' while the Democrats are a ''pack of pessimists roaming the land.''
* He wants to bring down tax rates for everyone. If Mondale were elected, this would mean a $1,800 to $3,000 tax rise for every taxpayer.
* The President seeks to restore traditional ''family values.''
Political analysts seem agreed that at this juncture the public is still more attuned to personalities and qualities of leadership than it is to specific issues.