Primary Election Day is Tuesday. The 20th-century politician and diplomat Adlai Stevenson said, "As citizens of this democracy, you are the rulers and the ruled, the lawgivers and the law-abiding, the beginning and the end."

Translation: Vote responsibly.

There are a number of items on the ballot, from a bond issue that largely benefits state transportation projects to party nominations.

When Maine Democratic Rep. Tom Allen, who represents the state's 1st District in Congress, decided to leave his seat and challenge Sen. Susan Collins in her re-election bid, a gaggle of ambitious Democrats jumped at the chance to replace him.

They are: Michael Brennan, Chellie Pingree, Steve Meister, Mark Lawrence, Ethan Strimling and Adam Cote. The Democratic race to determine who will face a Republican in the general election has been a lively and, in recent days, even bitter contest.

The Republican primary race for the 1st District has been tamer, largely because only two candidates are in that contest, Charlie Summers and Dean Scontras.

This newspaper does not endorse in primaries. We believe that an endorsement should be given to the candidate we think is best suited to hold the elected office, and so it would be illogical to endorse a candidate representing each party. So we will save our endorsement for the general election.

In the meantime, though, we offer these thoughts as Maine voters consider their choices in Tuesday's primary.

Congress was invented by the wise people who put our government together a couple hundred years ago so that Americans could be represented by a separate, equal and independent federal governing body -- separate, that is, from the executive branch, equal to it and independent of it.

So the job of a member of the House of Representatives -- known as the "People's House" -- is both grand and intimate. Grand in the sense that members must practice oversight of the president, the president's cabinet and the agencies they control, and intimate in the sense that a congressman is the representative of thousands of people back home whose interests must be understood and promoted.

That takes knowledge both expansive and particular.

In Congress, you've got to understand foreign policy (so that you can exercise congressional prerogative to declare war), as well as how much a failing septic system can cost a constituent (because there could be federal grants to fix that system).

You've got to be willing to transcend party interests in the name of state interests and you should be willing to deal in order to get things done for your district.

Lyndon Johnson, a legendarily wily and effective representative-turned-senator-turned-president, once said "I am a compromiser and a maneuverer. I try to get something. That's the way our system works."

With that in mind, consider the candidates in Tuesday's primary. Are they idealogues and one-note charlies, bent on pursuing one issue and one point of view above all else?

Or are they polymaths, educated about many things and interested in many others?

Are they in touch with the people in the district they want to represent? Or are they insulated and aloof? Can they listen well?

Are they creatures of a party apparatus that wants to keep hold of a seat and beholden to interest groups who will want their continued allegiance? Or are they independent-minded, with strong beliefs of their own?

Are they wise? Principled? Or will they blow in the wind?

Adlai Stevenson was right: You, the citizens of this state, are the rulers and the ruled. That means if you want a good government, if you want to be ruled by fair, wise and capable leaders, you must choose well.

In an age when it is common practice to trash-talk Congress for being corrupt, unresponsive and ineffective, we must remember that we have elected the very people about whom we're complaining.

But if we vote simply along party lines, or in thoughtless response to hot issues, or for someone we know little-to-nothing about, then we get the government we deserve.

So go study your choices -- and then vote.