US election 2010: The fable of the endangered incumbent
The headlines scream the names of defeated incumbents. Both parties are losing senior members of Congress across the country. Every primary election night brings a higher toll.
Senator Bob Bennett (R-Utah) falls, then Senator Arlen Specter (D-Pennsylvania) - and Senator Blanche Lincoln (D-Arkansas) only just survives despite the avid support of the only Arkansas native ever elected president, Bill Clinton.
Longtime incumbent Representative Alan Mollohan (D-West Virginia) is now a lame duck, and so is Representative Parker Griffith (R-Alabama).
And don't forget Governor Jim Gibbons (R-Nevada), badly defeated in his bid for a second term.
Will there be more victims during the long American primary season that doesn't end until September? Of course. Is the total of four incumbent congressmen and one governor unusual? Not at all.
Over the past 40 years, the average number of representatives and senators defeated in primaries has been between six and seven per election year.
The politicians defeated so far in 2010 were juicy targets for one reason or another.
Mr Specter and Mr Griffith are party-switchers. When a politician changes his party label, he is hated by his old party and distrusted by his new one.
Mr Mollohan and Mr Gibbons have been investigated for corruption.
Mr Bennett was a victim of internal party fissures - regarded as too moderate by the party ideologues who voted. Ms Lincoln faced the same problem.
Quietly, while the media have understandably focused on the fall of a handful of powerful legislators and executives, fully 200 members of Congress have been re-nominated by their parties so far.
Many were unopposed and most didn't break a sweat to gain their berth on the November ballot. It doesn't take a seer to predict that this pattern will continue all season.
We are talking here about party primaries (and a few party conventions). The turnouts are quite low compared to a general election, and the participants are usually the most dedicated party activists who know the incumbents, have supported them previously, and mainly approve of their stances on the issues.
It is true, on the Republican side at least, that Tea Party backers are participating in GOP nominating contests, and this adds a new element of potential surprise.
Yet the Tea Party is seriously contesting only a small portion of the Republican nominations for Congress and governorships, and in many cases Tea Party devotees are friendly to the sitting incumbents.
Many polls show that enormous majorities of Americans of all stripes are dissatisfied with Congress and give it an unfavourable rating.
But voters do not cast a ballot for "Congress".
Instead, they vote for or against their own senators and representatives. People often exempt their members of Congress from the condemnation of the institution, either because they like the legislators personally or appreciate the pork they bring home.
None of this is to say that major changes aren't coming in November.
In fact, Republicans are nearly guaranteed to pick up two to three dozen seats in the House of Representatives, and with a few breaks, they could actually gain the 39 seats needed to take control.
In the Senate it is unlikely the GOP will win the 10 seats they need for a majority, but a sizeable addition of five to seven seats is quite possible - leaving the Democrats with a minimal majority in the unruly upper chamber.
In addition, Republicans will probably pick up six or seven net governorships out of the 37 on the ballot.
The Republican Party will have a good autumn because the economy is bad and President Obama's approval rating is hovering below 50%.
Plus, Democrats have won more than 50 seats in the last two elections, in substantially Republican territory. There will inevitably be giveback, just as there usually is in mid-term elections.
But you won't be able to predict the magnitude of November change from looking at the primaries.
The most significant mid-term election in modern US history was in 1994, when Republicans picked up 52 House seats and nine Senate seats to win both houses of Congress for the first time in 40 years.
In that cataclysmic political season, exactly how many congressional incumbents lost in all primaries taken together? Four House members and no-one in the Senate.
Dr Larry J Sabato is director of the Center for Politics at the University of Virginia and editor of Larry J. Sabato's Crystal Ball.