The quotations come back redacted, stripped of colorful metaphors, colloquial language and anything even mildly provocative.

They are sent by e-mail from the Obama headquarters in Chicago to reporters who have interviewed campaign officials under one major condition: the press office has veto power over what statements can be quoted and attributed by name.

Most reporters, desperate to pick the brains of the president’s top strategists, grudgingly agree. After the interviews, they review their notes, check their tape recorders and send in the juiciest sound bites for review.

The verdict from the campaign — an operation that prides itself on staying consistently on script — is often no, Barack Obama does not approve this message.

The push and pull over what is on the record is one of journalism’s perennial battles. But those negotiations typically took place case by case, free from the red pens of press minders. Now, with a millisecond Twitter news cycle and an unforgiving, gaffe-obsessed media culture, politicians and their advisers are routinely demanding that reporters allow them final editing power over any published quotations.

Quote approval is standard practice for the Obama campaign, used by many top strategists and almost all midlevel aides in Chicago and at the White House — almost anyone other than spokesmen who are paid to be quoted. (And sometimes it applies even to them.) It is also commonplace throughout Washington and on the campaign trail.

The Romney campaign insists that journalists interviewing any of Mitt Romney’s five sons agree to use only quotations that are approved by the press office. And Romney advisers almost always require that reporters ask them for the green light on anything from a conversation that they would like to include in an article.

From Capitol Hill to the Treasury Department, interviews granted only with quote approval have become the default position. Those officials who dare to speak out of school, but fearful of making the slightest off-message remark, shroud even the most innocuous and anodyne quotations in anonymity by insisting they be referred to as a “top Democrat” or a “Republican strategist.”

It is a double-edged sword for journalists, who are getting the on-the-record quotes they have long asked for, but losing much of the spontaneity and authenticity in their interviews.