JEFFERSON CITY, Mo. — This past week, another chapter was added to the saga of “Jason’s key.”

It was added by a Missouri Supreme Court decision that likely will have a major impact on the role of special interest money in Missouri government and the upcoming campaigns.

The phrase “Jason’s key” might seem to have no relationship with campaign finances or ethics. It doesn’t.

And that was the point of the state high court’s decision.

The word key in the phrase “Jason’s key” refers to a key that opens access to a very high place in Missouri government. Jason refers to Sen. Jason Crowell, R-Cape Girardeau, who has wanted copies of that key for legislators.

The key opens access to the loftiest floor in Missouri’s Capitol. Up there is the whispering gallery, high above the Capitol rotunda seal. Tour guides tell me it’s one of the few American spaces designed with perfect acoustics so that a whisper said against the wall can be heard clearly by someone on the other side of the circular wall.

For many years, only staff of the governor had access to that key. That aggravated Crowell. He argued that lawmakers regularly have groups of schoolchildren who would like to see those loftier locations in the Capitol.

Administration staffers argued it was an unsafe place. Getting there takes you through what amounts to the attic of the Capitol — a location where years ago I found an empty whisky bottle dating to the early 1900s.

In 2010, Crowell got the Legislature to stick his dome-key bill onto an omnibus bill that had grown from a simple item on state government contract procurements to a massive package of ethics and campaign finance restrictions.

The “Jason’s key” issue might not have had much to do with procurements, but so what? After all, procurement had nothing to do with all the other provisions added to the bill — such as making it a crime for the governor to offer a job to a legislator to get the lawmaker’s vote, restricting the shifting of campaign funds among political committees, stronger enforcement powers of campaign finance violations, tougher penalties for lobbyists who file false information and tougher campaign finance disclosure requirements.

The advantage of putting “Jason’s key” into that bill was getting the signature of the governor. Gov. Jay Nixon had vetoed a bill with a provision for Jason’s key the year before. But, on the other hand, Nixon really wanted the tougher laws on government ethics and campaign finance disclosure.

So, the Legislature essentially offered Nixon a deal. Sign the bill with “Jason’s key” and the governor would get those other provisions he wanted. The governor agreed and signed the bill.

But now, Missouri’s Supreme Court has issued a ruling essentially telling the Legislature and the governor that they are prohibited by the state constitution from making the kind of deal that involves “log rolling” more than one issue into a single bill.

The constitution requires that a bill be limited to one subject. Further, it prohibits the Legislature from expanding the scope of a bill beyond the original version when it was introduced into the Legislature.

In its unanimous decision, the court cited those provisions and concluded that “the sections relating to campaign finance, ethics and keys to the Capitol dome are not logically connected or germane to procurement,” which was the original purpose of the bill.

So just as the 2012 campaign heats up, the court has thrown out a major package of legislation designed to provide more transparency for voters about special interest money in campaigns and to give the Missouri Ethics Commission stronger powers to enforce those laws.

Were it not for term limits, legislators might have known better. In a couple of decisions decades earlier, the court clearly had warned lawmakers that this kind of “log rolling” was banned by the constitution.

But with term limits, those cases seem to have been forgotten. Long-time lobbyists have been predicting that the Legislature’s increasing habit of tossing unrelated issues into a bill was going to come back and bite the General Assembly.

It finally has.

I have a friend, David Valentine, in the Truman School of Public Administration, who runs the Legislative Academy — it provides new lawmakers with a background on basic legislative issues, including the requirement that a bill be limited to a single topic and not expanded beyond its original scope.

But clearly, a short presentation does not make up for the loss of institutional memory by lawmakers who used to have decades of history in the legislative process.

On the other hand, Nixon says he is not so sure this is a reflection of term limits. With a chuckle in his voice, he notes that this kind of legislative strategy was used well before term limits. “Log rolling of bills was something that was done many, many times, and many, many years it was attempted.”

As for “Jason’s key,” it’s still around in the law. Crowell got that provision stuck into a couple of other bills that became law in 2010 and remain in effect.

That is not the case, however, for the tougher campaign finance disclosure and ethics requirements about which the governor and legislators had bragged just two years ago. There was only one bill with those provisions, and now those provisions are gone.

Phill Brooks is director of the Missouri School of Journalism’s State Government Reporting Program. He can be reached at column@mdn.org.