The 2010 electorate has swallowed an emetic — disgorging in a series of retching convulsions officeholders in both parties who seem to embody conventional Washington politics.

The anti-establishment, anti-incumbent fevers on display Tuesday are not new. The ideologically charged, grass-roots activists flexing their muscle in this week’s primary showdowns are the same breed as primary voters who four years ago stripped the Democratic nomination away from Sen. Joe Lieberman of Connecticut, who later won as an independent.

What’s now clear, in a way that wasn’t before, is that these results reflect a genuine national phenomenon, not simply isolated spasms in response to single issues or local circumstances.

This is a stark and potentially durable change in politics.