Mindful of public support for President Reagan, the US Congress in its first session helped launch a budget revolution of sorts designed to get the economy moving again. Now, as it reconvenes for its second session, the question is whether it will have the fortitude to adopt the measures needed to correct flaws and gaps in the Reagan recovery program. This being an election year, lawmakers will be strongly tempted to play to the galleries back home. It will take enormous political courage not to let the national interest become hostage to local pressures.
Among such pressures will be calls for action on such social issues as busing and abortion. These are extremely complex and controversial issues in themselves, requiring thoughtful study and deliberation, and it would be a pity if they commanded center stage and were allowed to frustrate the crucial economic agenda. The economy remains the country's overriding problem. With a recession in progress, unemployment at high levels, and a budget deficit of $100 billion or more forecast for fiscal 1982, the Congress and the administration would be letting down the public by anything less than single-minded attention to correcting these conditions.
It is possible, of course, to exaggerate the impact which budget deficits have on the massive US economy. Yet it is generally agreed that they do contribute to inflationary pressures and reduce private capital formation - precisely the reverse result of what is now desired. What is less agreed on is what combination of measures to adopt in order to bring the deficits down. The President for political reasons now seems to be reluctant to raise new taxes, though it would be logical to boost revenue through higher excises on such items as liquor, cigarettes, and gasoline.
An even larger source of revenue, however, lies through tackling those areas of public spending which went by the board in the first round of presidential cuts. Here is where fortitude comes in. It was relatively easy to reduce the social benefits of constituents who have little political voice. But the time has come to make changes in social security and in the other so-called entitlement programs - government pensions, medicare, veterans' benefits - which account for a gigantic share of the federal budget. Also, to tackle the whole area of ''tax expenditures'' - those special tax exemptions and deductions which cost the government billions of dollars annually.
The low-income segments of society, in short, should not be asked to bear the biggest burden of federal spending cuts. Fairness dictates that the middle and upper classes share equitably in the reform process.
Finally, there is military spending, a perennial area for close scrutiny. President Reagan is determined to hold to his huge defense budget increases - 7 percent annually over the next five years - but there are few defense experts who do not cite enormous areas of waste that could be profitably cut. Many economists, moreover, warn that an accelerated military buildup risks aggravating inflation, crowding out business in the competition for materials and labor, and hurting productivity. It goes without saying that the legislators, without impairing the national security, have an obligation to restrain an excessive buildup which could hurt economic recovery - and thereby impair the very strength of the nation which the administration seeks to bolster.
The legislators of the 97th session thus have a weighty agenda. It would be unrealistic to expect them not to keep one eye on their constituents as they set about making difficult decisions. But voters have more sophistication than they are generally given credit for, and we suspect that in the long run they will be supportive of sound, well-explained reforms that hold out promise for a stronger economy - if the lawmakers have the courage of their convictions and are willing to take the political heat. Will they rise to the challenge? The economy - and the national well-being - will be the better for it if they do.