The events of the last seven weeks have shown a significant contrast between the Democrats and the Republicans. The Republicans faced a very similar situation to this back in June, when Tom Tancredo tried to purge Chris Cannon from the GOP for favoring a comprehensive immigration bill that would have picked up significant support across party lines. That purge failed, and Cannon won.
The Democratic primary was a similar situation. The MoveOn/DailyKos/DU crowd was after Lieberman because he felt that partisanship stoppd at the water's edge. For that, he was purged.
If the Republicans are smart, they'd dump the candidacy of Alan Schelsinger, and instead endrose Lieberman. Lieberman gets the big issue right - and it's time to make it clear that the GOP is not the party of cut and run.