Real Clear Politics' Sean Trende -- if you don't read him, you should -- penned a very important piece this week on the tendency of the political class to overreact to events, to assume that everything is a game changer (with apologies to John Heilemann and Mark Halperin) that has the potential for permanent political change.

Bored girl in classroom with stack of books

Here's Trende writing about the doom-and-gloom predictions that the struggles of Obamacare might lead to the destruction of the Democratic Party and even the idea of liberalism:

I’ve said before that our press corps suffers from histrionic personality disorder, and this is but the latest example. Wasn’t it just weeks ago that we were told the government shutdown could cost Republicans the House? But elections and the ideological orientation of the country don’t turn on such immediate, short-term events. The arc of history is long. Both parties, and both ideologies, have plenty of wins ahead of them, and neither is likely to suffer a knockout blow.

He goes on to document a series of historical examples -- from Grover Cleveland to Richard Nixon and more -- in which a series of events led one party to believe that it was headed for an extended period of dominance only to be proven wrong in relatively short order. To Trende's excellent list, we'd add the famous/infamous vision of Karl Rove's "permanent Republican majority," a prospect that didn't seem all that unrealistic following George W. Bush's reelection (and unified Republican control of both congressional chambers) in 2004. Just a year after Bush's reelection, however, Slate's Jacob Weisberg penned a piece entitled "Karl Rove's Dying Dream" that detailed the political doldrums in which Bush found himself -- doldrums that only worsened after Democrats won the House and Senate back in the 2006 election.

At the heart of the pendulum-swinging nature of politics is the tendency of both parties to misunderstand their mandate. Look at the last five years. President Obama was elected overwhelmingly in 2008 on a message of "hope and change." But, after spending much of his first term pushing through the Affordable Care Act, Obama watched his party lose more than five dozen seats -- and its majority -- in the House in the 2010 election.

Republicans, emboldened by their midterm gains, assumed that Obama's 2008 victory was the exception, not the new normal in politics. Misunderstanding their mandate, they assumed the country had voted for them and their agenda in 2010 as opposed to voting against Obama and, in particular, Obamacare. Whoops! The 2012 election drove home the reality that the demographic, geographic and ideological problems that the party had in 2008 had gotten worse, not better, in the intervening four years.

All of which brings us to today -- with endangered Democrats trying to get out from under the political problems caused by Obamacare and the president grappling with the lowest job approval of his time in office. Again, Trende:

This isn’t to say that a collapse of Obamacare would be without consequences. It would probably ruin the Democrats’ chances in 2014, perhaps leading to truly significant Republican gains in the Senate. Given that that chamber tends to be a natural Republican gerrymander, it would probably take Democrats some time to recover. But also given the current makeup of the House, further liberal legislation was likely going to have to wait for quite some time anyway.

As we have written, Republicans must be careful not to conflate the very real possibility that they will have a strong 2014 midterm election performance with it meaning anything about their chances in 2016. The worst thing for the party -- and a number of smart GOP strategists have already voiced this worry to us -- would be to assume that a 2014 victory fueled by anti-Obama sentiment is the panacea to what ails the party long term. It isn't -- and to assume it is would be to repeat the mistake the party made in 2010/2012.

The political pendulum swings --faster now than ever due to the sped-up metabolism of how the culture consumes information. Permanent majorities don't exist. Mandates  are forever misunderstood.