Other than possibly flip control of the state House, the undecided races signal how far Democratic Party has come in the Philadelphia region's most loyal Republican county.
As Montgomery, Bucks and Delaware counties have gone Democratic in races at the top of the ticket (president, governor), and occasionally for state legislative seats over the last 14 years, Chester County has resisted the trend.
But then came Andrew Dinniman, the Democratic county commissioner who won a special election in May to fill a state senate seat. It was an upset, and it gave his party a foothold in the county.
Dinniman quickly came to Barbara Smith's aid, said Lani Frank, who became Smith's campaign manager after finishing her work on Dinniman's campaign.
Dinniman asked his supporters to work for Smith and his contributors to write checks. That kind of back-up is crucial for a Democrat when voter registration numbers favor the Republican.
If Chester County sends a second Democrat to Harrisburg, it means the party has an even better shot at claiming more seats in the future.
In this region, a political keystone in presidential campaigns, seemingly small changes of party control can reverberate far beyond the state.
Republicans could be compared to doctors in flu season: hope the cases remain isolated.