Certain positions in the administration have become almost impossible to fill.

ECONOMIST: Presidential nominations

Last year this made it impossible for Mr Clinton to fill the top civil-rights job at the Justice Department.

ECONOMIST: Presidential nominations

This is arguably hardest in services, though not impossible: even journalists find that work expands to fill available hours.

ECONOMIST: Economics focus

"How are London schools ever going to fill their vacancies when faced with an impossible situation such as this, " said the union's general secretary, Peter Smith.

BBC: Motorway

But without the foundation of SNAP benefits, it would be impossible for food banks, pantries, and soup kitchens to fill the gap and provide enough food to meet the need.

WHITEHOUSE: Champions of Change Blog

If, as seems likely, the new Homeland Security Department is unable or unwilling to take on this task even though it will be impossible to succeed in its mission without doing so the Congress must fill the vacuum.

CENTERFORSECURITYPOLICY: Center For Security Policy

"Essentially, we have hard-working Mexicans who are coming to fill jobs that would otherwise go unfilled, but our immigration laws make it impossible for them to do that legally, " said Frank Sherry of the National Immigration Forum.

CNN: Wallace