Disinformation about earmarks is being widely disseminated by some politicians and the media, but if most people are by now confused, that is no reason you should be.
Members of Congress get frustrated when programs they promote are administered in ways they never intended. Unelected government employees who live no more than a few miles from the U. S. Capitol often wind up having far more to say about how federal money is specifically spent than do the elected officials who appropriated it with their home states in mind. Once federal administrators get a hold of them, the funds effectively are theirs to deploy on the basis of criteria they interpret. It may come as a shock to you, but it happens that some bureaucrats have their own pet projects and their own agendas.
That is how earmarks came about. Congressmen and senators whose seniority or other committee positions provide them influence on the passage of a bill negotiate to make sure that the post office construction program they were funding includes the building the member from Texas or California believes has been too long neglected in his state. It probably happens too often in defense spending and leads to inefficiencies that have incensed presidents going back to at least Franklin Roosevelt. The multi-billion dollar highway bill is especially notorious as a Christmas tree for powerful members who want to assist the transportation needs of their communities. The chairman of the committee in each house typically gets the lion's share of top project picks, and the ranking member of the opposition party also gets a small number as a way of assuring bi-partisan passage of the bill. Less significant members scramble to get their state's favorite projects established.

To the left - Artist's rendition of the "Bridge to Nowhere." And...."Nowhere"
Regardless, earmarking is sometimes a good thing. Elected officials often do have a better feel for the public good than bureaucrats, especially when the subject is something innovative; say, a new way to produce energy, a model historical preservation project or a pilot program for increasing traffic flow. The representative who comes up with a fresh idea understandably wants to have something to say about how--and where--it is implemented. When you are that representative, and you have been urged by constituents to provide leadership on some key concern in your state, having the bill you managed to pass turned into something very different at the executive level is past irritating. It leads you to get your state's project specifically included in the enacted bill.
The hypocrisy of campaigning "against earmarks"--or of media deriding them in principle, when the same media often have demanded specific action from local elected representatives in the past--is also past irritating. It is downright unfair. If earmarks are bad, per se, then, by all means, let the exposes begin on all the earmarks proposed and adopted by today's Congressional leaders. Immediately you would hear cries of, "Oh, but that particular highway connection, or museum, or whatever is very desirable and needed!" In other words your "pork" is my "wise investment".
So, realistically, the problem with earmarks is mostly that their use got completely out of hand in recent Congressional sessions. The sometime habit became a dangerous addiction. In the 90s when Republicans came to power, their political base of conservative voters expected them to cut costs, but GOP leaders who had chaffed for years as the Democratic majority employed earmarks to gain electoral advantage, vowed to equal or surpass their free-spending Democratic colleagues. They also were more distrustful of the generally liberal bureaucracy in Washington and its priority-setting than was the previous, Democratic majority. Therefore, instead of restraining the earmark habit, they decided to indulge it. Earmarking was expanded and, ultimately, abused. Maybe if Democrats were still doing it, nobody would have cared. But Republicans did it and people did care. It was a mistake. But that's politics.
Surely someone could cover this issue in a serious, nuanced way. "Bringing home the bacon," after all, is a time-honored political accolade for any party, almost any time. Republican Sen. Ted Stevens of Alaska, who is now reviled for over-indulging in earmarks, obviously learned at the feet of such giants as Democratic Sen. Warren G. Magnuson of Washington and their long-serving, still-kicking colleague from West Virginia, Democratic Sen. Robert Byrd. When whole federal government offices are resettled in the mountains and dells of Byrd's home state, observers just chuckle.
But opinion began to turn against earmark abuse two years ago with publicity about the "Bridge to Nowhere" that the Alaska delegation sought as one of its public works trophies. It was a bridge too far, as many editorialists said. And Stevens got stuck with the blame. Instead of graciously giving up, he expressed outrage at the hypocritical resentments raised about the project. He was right that the $398 million project did have merit, since it would have given mountain-locked Ketchikan a link to the island where its airport is located and would have opened up the island for development. It was just far too expensive to justify and should have been abandoned.
Congress ultimately got rid of the specific earmark, but still allocated the money it represented to Alaska to spend. It could have gone to the "Bridge to Nowhere," after all, but Gov. Sarah Palin turned against the project and reprogrammed the funds.
Why would anyone be surprised that a governor initially supported the award of funds to help her state? Why would anyone be surprised that the savvy governor later would realize that the point of excess had been reached and called for reform? It's not like a change of position on a moral issue, but rather a recognition that a defensible political tactic had gotten out of hand.
Unfortunately, in the next two months you are not likely to hear the kind of modulated position I have just stated, but, ironically, it is what almost everyone--including leaders of both parties in Congress--holds.
I suspect that even Sen. Stevens wishes now that he had taken it, too.
Meanwhile, you can be sure that come January and a new Congress, there will still be earmarks, regardless of which party is in charge.