Can a party possibly win too many House seats? That may be tested soon in New York, where the Democrats already hold 26 of the 29 seats -- and soon will be making a bid for one more.

Surely they will make a run at the far northern 23rd District represented by nine-term Republican John M. McHugh, who was nominated by President Obama to be secretary of the Army and will vacate his seat if (as expected) he is confirmed.

McHugh, a mild-mannered and conciliatory conservative, was able to win his House elections by landslide margins. But his district -- like most former Republican strongholds in the Northeast -- has trended Democratic at the top of the ticket, giving Obama 52 percent and a 5-point margin over Republican John McCain. The only state bordering the 23rd District is Vermont, a historical GOP stronghold that has evolved into one of the nation's most liberal- and Democratic-leaning states.

Yet if the Democrats manage to win the special election to replace McHugh and hold the seat in 2010, it could actually complicate the party's ensuing efforts to gain advantage in the congressional redistricting that will precede the 2012 elections.