An interesting thing has happened since Pennsylvania Sen. Arlen SpecterâÄôs Tuesday announcement that he was leaving the Republican Party to join the Democratic caucus. Rather than express concern that SpecterâÄôs defection may give Democrats a filibuster-proof 60-seat majority in the Senate, or talk about the dissatisfaction they must feel over losing a 43-year veteran of the party, Republicans have taken a bitter and haughty posture as though theyâÄôre doing Specter a favor by suffering him to leave. Considering their recent electoral record, they should not be so cavalier; all assurances to the contrary, actions like these cement the GOPâÄôs reputation as the party of southern white males and will cause the eradication âÄî not emergence âÄî of effective political diversity. By declaring itself to be disinterested in moderates like Specter, Republicans are making the costly decision to dismiss a constituency of voters and politicians whose appeal are broad and whose support was up for grabs. Since American politics is strongly rooted in the two-party system and its political capital is hoarded by the two major parties, when the GOP makes people like Specter feel unwelcome, they estrange voters who arenâÄôt going to join third parties; like Specter, theyâÄôll simply depart one power base for another. In the words of another moderate Republican, Olympia Snowe: âÄúIdeological purity is not the ticket back to the promised land of governing majorities âĦ we cannot prevail in the future without moderates.âÄù We hope diversity and moderation prevail in the Republican Party, because it if does not, they will be left a powerless minority. Without power, there is no opposition party, and without opposition, we lack practical democracy.