In 2008, the New Hampshire Senate became the first legislative body in America -– and only the second in the world after Rwanda’s Chamber of Deputies -– to elect women to a majority of its seats.

On Monday, the U.S. House of Representatives passed a resolution honoring the achievement. But this important milestone may be part of a broader trend in America’s state legislatures -– as more Democrats are elected as legislators, more women are elected as well.

According to a National Conference of State Legislatures report on the demographics of state legislatures, 23 states (almost half the country) elected women to at least 25% of their legislative seats. An overwhelming 17 of those states have Democratic majorities in both chambers, and two more are under split control.

The difference is even clearer when the threshold is increased to 30 percent. In the 11 states where women hold at least 30 percent of the legislative seats, Democrats control both legislative chambers in 10 of them.

We’d encourage everyone to check out the report to see where your state ranks. And in case you’re wondering, a full eleven of the 13 women in the New Hampshire Senate are Democrats.

What do our legislators do for a living? How old are they? How many of them are women? How many are racial or religious minorities? Clearly, the number of Democrats and Republicans in elected office is not the only thing that matters, which is why we’re so excited that the National Conference of State Legislatures has created a new tool to help answer those questions and more.

The graphic allows individuals to compare the demographics of their state legislature against any other state, as well as national averages. I was surprised to learn, for instance, that my home state of Louisiana has fewer clergy members serving in its state legislature than New York does, but more than three times as many doctors (by proportion).

Morgan Cullen over at The Thicket took a look at broader trends and sought to explain why such a high percentage of legislators are from the “baby-boomer” generation:

Our analysis of state legislator ages in 2008 shows that 47.9% of legislators presently serve between the ages of 50-64 years of age. This age range accounts for nearly half of all legislators presently serving and is almost two times larger than any other age group.

There are many contributing factors to why a majority of legislators decide to run for elected office during this period of their lives. Candidates running for office from this age group have a broad range of professional experience making them more electable. Family responsibilities have often been significantly reduced since children are often fully grown. And the 50-64 age group is also the most financially stable, a benefit of many productive years in the workforce.

There is a wealth of other data available in the NCSL tool, and we’d encourage anyone to take a minute and check it out.

New York is another big state with a closely watched legislative contest. Republicans currently hold a one seat majority in the state senate, and control of the chamber could have a significant impact on Congressional redistricting after the next census.

Much of the attention is focused on competitive districts in the western part of the state, which is not historically a heated battleground for political races. Last week, the New York Times looked at the contests in the area and discussed the changes that have put the region into play:

The shift in the political terrain has become clear only in recent months, taking both parties by surprise and spurring Republican and Democratic officials to rapidly retool their strategies, particularly in the pivotal campaigns for the State Senate, where Republicans hold a one-seat majority.

The parties have poured hundreds of thousands of dollars into a series of Senate races in western New York that could decide control of the chamber for years.

Perhaps no immediate factor has done more to put the region into play than the financial crisis, which has hit Western New York particularly hard. But the area's demographics have changed as well, with the number of Republicans decreasing while the population of Democrats and Independents is on the rise.

Democrats will need to do well here on Election Day if they hope to put win control of the upper chamber for the first time in almost 70 years.

In Pennsylvania, longtime Republican strongholds in counties throughout the state are slowly shifting away from the GOP.

On Thursday, in Dauphin County -- which includes the state capitol of Harrisburg -- the numbers of registered voters looked like this: 81,489 Democrats and 81,340 Republicans.

In Philadelphia suburbs like Bucks and Montgomery counties, the trend is the same.

Waves of new Democratic voter were registered during the heated primary contest between Sens. Barack Obama and Hillary Clinton. That month of intensive campaigning certainly helped to put some areas over the top.

But this change is part of a longer-term demographic trend, and the end of the primary hasn't stopped the movement:

Statewide, Democrats have added voters since the April 22 primary, picking up 37,529 registrations while Republicans have lost 1,504, according to figures from the Pennsylvania Department of State [...]

From November 2007 to April's primary, the Republican Party lost 58,119 registered voters.

We still have a lot of work to do between now and November to maintain our control of the Penn. House, but information like this is heartening.