The U.S. Capitol in Washington is illuminated as the debt-limit stalemate continues Saturday night, July 30, 2011. (AP Photo/J. Scott Applewhite)

Need more evidence of just how unhappy the American public is with Congress?

Look no further than today’s NBC/Wall Street Journal poll where 54 percent of those tested said that if they had the opportunity to vote out every single Member of Congress — including their own — they would take it.

That’s the highest that number has been in the 18 months or so that NBC/WSJ have been asking the question — and the clearest evidence yet that we may be headed to a “pox on both your houses” election the likes of which we have never seen before.

Obviously there is no place on the ballot where you can vote out every incumbent — though it would be kind of fascinating if there was, wouldn’t it? — and elections are fought district by district, not in a single national vote.

But, the NBC/WSJ poll question provides a helpful barometer of he discontent that people are feeling toward Congress generally and also gauges how willing — at least at the moment — they are to act on those feelings.

Looking back on the (relatively) short history of the question, the new numbers are jarring.

Just before the 2010 election — where Republicans picked up a whopping 63 House seats — just 45 percent of those polled said they would vote out every incumbent including their own.

That the number has now risen to 54 percent suggests that the 2010 election, which many people cast as a moment of closure for voters wanting to vent their unhappiness with Washington, was actually just a midpoint in an ever-increasing displeasure with how the nation’s capital and its inhabitants operate.

(Another piece of evidence that speaks to that unhappiness: 82 percent of people disapprove of how Congress is handling its jobs in the NBC/WSJ poll — the highest number in the survey ever; in the new Washington Post/ABC News poll 68 percent disapproved of how Republicans in Congress are doing their job.)

As we have written before, there is no historical precedent for voters throwing out large numbers of incumbents of both parties in a single election. Blame tends to congregate around a single party — usually the one perceived as being in charge in Washington — rather than being spread out to both sides.

But, we are living in historically anomalous political times. The eye-popping disapproval numbers for Congress, the large number of people who say the country is headed off in the wrong direction and the ongoing economic malaise are creating a strange brew that we’ve not witnessed before.

Yes, we are still a long way from the 2012 election. And, yes, plenty will almost certainly change between now and then.

The poll numbers we are seeing these days, however, are unlike any in modern memory. If you’re an incumbent — of either party — it’s going to be a rocky next 14 months. Buckle up.