ATLANTA — Since aides and advisers resigned in early June, Newt Gingrich's presidential bid has been on life support.

And his first campaign finance disclosure filed on Friday provided little reason to be optimistic. Gingrich has raised $2.1 million since getting into the race earlier this year, badly trailing front-runner Mitt Romney.

But perhaps more problematic is that he has a little more than $1 million in debt, almost half of that for private air travel.

Gingrich's campaign remains a skeleton operation. He has not moved to replace most of the consultants and staff members who left. Gingrich argues the kind of grass-roots, Internet-driven campaign he wants to run can function with a lean staff and he doesn't need a stable of well-paid consultants.