Term limits are often compared to turning over a garden — regular tilling loosens things up, lets the sun shine in, allows the fresh air to circulate. With the Maine Legislature now in its second term-limited edition, it may be time to rethink the growing season.

Overall, the term-limits law passed by voters in 1993 is good. It guarantees fresh blood and new ideas and helps offset the undeniable advantages of the incumbent. By making the job of the challenger less formidable, the law may attract to public service good people who otherwise wouldn’t try.

But four terms — eight years — may not be long enough. Not just for the average taxpayer from the hinterland to become an effective and knowledgable lawmaker in Augusta, but for the average lawmaker to become a leader. Senate presidents, House speakers and whips are made, not born, and good ones aren’t made overnight.

The 1993 referendum passed by a wide margin, with nearly two-thirds in favor of capping legislators and constitutional offices (secretary of state, treasurer, attorney general) at four consecutive terms and leadership at three. And, unlike most states with term limits, it was retroactive; terms already completed counted toward the total.

It was a tough law, but so were the times. Maine was still struggling with recession as other states were well into recovery. There had been an embarrassing state government shutdown. There had been the Ballotgate scandal. That times are better now is no reason to doubt the worth of the term limits concept, but the historical context does help explain the law’s severity.

Now, there are five bills before the Legislature regarding term limits. Three ask voters to repeal a law they warmly embraced at referendum just a few years ago, which suggests the likelihood of those three bills going anywhere is virtually nil. One adds term limits to the offices of House clerk and Senate secretary, which seems utterly unnecessary, perhaps even spiteful, given the administrative nature of those jobs. Only one, to extend the limit to six terms, 12 years, deserves consideration by the Legislature and stands a chance with the voters in a referendum next year.

There are good reasons why lawmakers and voters should consider extending the limit. Maine has a citizen legislature, darned proud of it, but the learning curve for part-timers in any job is gradual. And few part-time jobs require a command of taxation, education, environmental and other complex public policy issues. Eight years is not as long as it seems when roughly two-thirds of it is spent back in the hometown doing the regular job. There are signs the legislature’s institutional memory is getting fuzzy; the growing tendency of one Legislature to undo the work of the previous demonstrates a lack of commitment and consistency. The sheer number of bills submitted this session, nearly 3,000, and the vague, ill-conceived nature of many suggests an atmosphere of haste, a desire by newcomers to make a mark and by short-timers to leave something behind. Any mark, any old something.

The idea behind term limits is to prevent entrenchment, not to create an endless parade of novices. There is nothing magic about eight years. It likely was chosen as the limit because that is the cap already imposed on governors and presidents. But governors and presidents usually come into their jobs having already proven an ability to lead. The nature of the Maine Legislature is that it is a traing ground for leaders. Lawmakers would be making a grievous mistake in trying to scrap a law so recently enacted by the voters, but they can make a case that tilling the soil does little good if the crop is not given time to take root.