1858, June 16: In Springfield, Illinois, Abraham Lincoln delivered his “House Divided” speech on his nomination for the U.S. Senate seat, running against Democrat Stephen A. Douglas.

We are now far into the fifth year, since a policy was initiated, with the avowed object, and confident promise, of putting an end to slavery agitation.

Under the operation of that policy, that agitation has not only, not ceased, but has constantly augmented.

In my opinion, it will not cease, until a crisis shall have been reached, and passed.

“A house divided against itself cannot stand.”

I believe this government cannot endure, permanently half slave and half free.

I do not expect the Union to be dissolved — I do not expect the house to fall — but I do expect it will cease to be divided.

It will become all one thing or all the other.

Either the opponents of slavery, will arrest the further spread of it, and place it where the public mind shall rest in the belief that it is in the course of ultimate extinction; or its advocates will push it forward, till it shall become alike lawful in all the States, old as well as new — North as well as South.

via “House Divided” Speech by Abraham Lincoln.

If one were to extrapolate to the partisan divide through the history of U.S. politics, rather than the divide between pro- and anti-slavery, one might observe that indeed a house divided can stand. In fact, to stand, a house must be divided, fairly evenly, with swings one way or another but balancing swings back, as predictable as a pendulum. Our bifurcated system is what keeps us able to magnify and then address our problems, when one side gets so agitated about a wrong that it is able to attract attention and energy on its side of the aisle.

In politics, we could oversimplify and identify the two parties as “slave” and “free” – with no disrepect meant to the original and odious issue of true human slavery. Here I mean slave to government, versus the liberty of the individual. A nation which pushes to be all one way or the other would devolve into either totalitarian hell, or hellish anarchy.

The tension between the two is what allows American politics to continue, and to represent and resolve complexity.