CONGRESSIONAL Democrats are looking with interest at a $4.3 billion job offer from the White House. Their leaders were right to agree to deal with the administration on a relief package that has some chance of quick passage. Demands for a much larger program may be good for Democratic electioneering, but they won't do anything for the jobless workers who need help right now. But the Democrats should also look closely at the details of the administration's proposals before deciding that the package is a good deal.

One component of the package should be non- controversial. That is the provision of humanitarian aid--food and shelter--to the homeless and destitute. The only concern in this regard should be that provision is made for getting the aid out quickly to the areas where it is needed most.

The job-creating parts will require closer scrutiny. What is known about the proposals thus far suggests that the administration is considering accelerating some federal construction projects and adding money to block grants made to cities for community development projects. Whether this makes sense or not depends crucially on the answers to some questions.

Are the projects the kind that can be started up quickly? States are already struggling to step up highway construction under the gas-tax-highway- repair legislation passed in December. That's not easy to do--especially in areas with severe winter weather, which also tend to be those with the worst long-term unemployment.

Will the money produce a significant number of jobs or will most of it go for equipment, supplies and high-wage costs? What will ensure that the jobs go to the long-term unemployed--especially those with families to support--rather than to new labor market entrants or people who can expect to find jobs relatively soon?

Is this new money or just faster spending of money already in the budget? If the latter, what happens when the money runs out?

Will the money go where it is needed? The location of federal construction projects is determined by the type of project (you don't need a dam in a desert or an irrigation project in the industrial Mid- west) and by the ability of congressmen to steer money to their districts. It would be a remarkable coincidence if that pattern happened to coincide with the distribution of long-term unemployment.

Community development block grants are broadly distributed among cities. But some cities have a less severe unemployment problem than relatively rural areas such as the iron-mining range of Minnesota or the small steel towns of the Ohio valley. HUD has also weakened federal control over the uses of these funds so that it will be difficult to be sure that cities don't just use the new money for things they would have done anyway.

Supporting jobs legislation may make both Congress and the administration feel good. But unless the proposal offers good answers to these questions, it may not do much to warm the hearts of the unemployed.