Just last fall, statewide offices were filled for another four years. Yet 2015 hadn’t yet entered spring before folks under the Gold Dome started speculating about the next round of elections.

The most discouraging thing about this year’s legislative session may be how obvious it was that a number of lawmakers already had 2018 on their minds. It was apparent in the types of bills introduced, the amendments offered to those bills, the votes cast on them. The transportation-funding measure was a prime example, as legislators with higher ambitions maneuvered with them in mind.

You can expect a certain amount of this before a second-term governor leaves office. But four years ahead of time?

It doesn’t bode well for legislators’ ability to tackle big issues soon. They’ll all be up for re-election in 2016. The 2018 campaign for statewide offices will begin shortly thereafter. As hard as it is for legislators to focus on legislating in election years, when the urge to gavel out and begin raising money hits them as inexorably as the salmon’s instinct to head upstream, next year might be the best hope for such major legislation as Gov. Nathan Deal’s education reforms.

But wait, it gets worse. Consider the recent exodus of longtime, powerful lawmakers from the House.

Gone are Majority Leader Larry O’Neal, to serve as a state tax judge, and Transportation Chairman Jay Roberts, the state’s new transportation planning director. Leaving as well are Reps. Mark Hamilton, R-Cumming, a quietly effective lawmaker; Tyrone Brooks, D-Atlanta, who ended his 34-year career to plead guilty to tax fraud; Mike Jacobs, R-Brookhaven, a newly appointed state court judge; and Harry Geisinger, R-Roswell, who served in four of the past six decades before passing away in May.

In fact, amid the frequent lamentations about career politicians, you may be surprised to learn how much turnover there is in Georgia’s Legislature.

I came to the AJC in 2009. For every nine legislators in office then, only four remain. That’s 55 percent turnover in just six years.

The changes reach to the top. Of the 13 members of the House leadership back then, only four are still in office; just two remain in leadership. It’s a similar story in the Senate, where just five out of 12 members of the leadership circa 2009 remain senators, two of whom are still in leadership.

There’s been commensurate change in committee chairmanships, a valuable currency for legislative leaders. Only two of 27 Senate committees have the same chairs as in 2009. In the House, it’s 12 of 38.

What those statistics mean in human terms is a steady departure of institutional knowledge, personal relationships and working alliances.

As appealing as arguments for term limits may be, this extent of turnover doesn’t necessarily help when it comes to much-needed reforms. Yes, there are smart people who arrive with fresh ideas. But there are also fewer people who have been around long enough to know how agencies and programs and policies work, how they don’t, and what might work better. I suspect that’s one reason it has been hard to get anything done in recent years without effort on the governor’s part.

All the more reason for legislators to act with more urgency in 2016 than they might like to exert in an election year.