Some of Mr Gingrich's financial involvements have long raised eyebrows, most notably the Gopac political action committee, which he leads and whose contributors he has steadfastly refused to name, and various taxpayer-funded TV shows and educational courses to promote his conservative views. All, say his foes, stretch electoral rules and tax laws to the limit.
None, though, has caused the fuss generated by the king's ransom HarperCollins is paying for two non-fiction books. The first, To Renew America, is due out next year in a planned print run of 750,000 copies.
Accusing Mr Gingrich of participating in a "sweetheart deal", David Bonior, incoming House Democratic whip, demanded an independent counsel to investigate the "ethical cloud" that had settled over him: "If this is not a gift, if there is no quid pro quo,then Mr Gingrich ought to tell us."
Mr Bonior's reference was to the Murdoch connection: that this windfall has arrived in the incoming Speaker's lap at the very moment the Fox TV network, also Murdoch-owned, is trying to persuade Congressional Republicans to relax rules governing foreign ownership of television stations.
Although Mr Murdoch is a naturalised US citizen, Fox is controlled through his News Corporation group, based in Australia. The watchdog Federal Communications Commission is investigating complaints by the rival NBC network that Fox is in violation of theexisting 25 per cent foreign ownership ceiling.
Mr Bonior's charge has predictably drawn a chorus of denials from all concerned. HarperCollins claims it only won the publishing rights after a bidding war with competitors, a Murdoch spokesman insisted the advance was not linked to the Fox controversy, while the media magnate himself declared during a visit to Peking that "This is the first I've heard of it."
Even so, the affair has been a heaven-sent opportunity for the White House and the Democratic party establishment to hit back at their most irritating and unnerving opponent.
Common Cause, a respected pressure group which monitors Congressional ethics issues, has also suggested the House Ethics Committee should look into the publishing advance and is urging Mr Gingrich to forgo his traditional privilege as Speaker and take nopart in nominating members to the committee, drawn equally from Republican and Democrat ranks.
The book payments, it is generally agreed, do not violate the letter of House rules that bar would-be authors from cashing in on "specific Congressional status". Mr Gingrich is an acknowledged superstar at a time when books by the former Vice President Dan Quayle, and Rush Limbaugh, a radio host, have been best-sellers.
The political spirit of those rules is another matter. The New York Times yesterday said the deal was a "serious tactical and ethical mistake," which "reeks of old-style Democratic greed".
Mr Gingrich, it added, should look to his own record. In 1989 he brought down a former Democratic Speaker, Jim Wright, who had received 55 per cent royalties on a book "peddled in bulk to lobbyists and other influence-seekers".Reuse content