Party Unity on Close Votes

While the majority of votes in the General Assembly have unanimous support from both parties, the closely contested votes are usually along party lines. In our review, we found that party unity changes with the margin of control in the legislature. The larger the majority, the more votes the party can afford to lose while still having enough to pass their agenda. But when a party holds a narrow majority, the tendency to vote as a bloc increases to ensure their priorities succeed.

Meanwhile, the party in the minority has less incentive to vote as a single bloc, since even a unified vote cannot overcome the majority. This is best demonstrated in the House of Delegates, where party unity for contested votes has flip-flopped as Republicans and Democrats have swapped control in recent years.

The chart below shows the share of close floor votes where all members of a party voted the same way.

Notes: Only includes close votes. VPAP defines a close vote as any roll call on the House or Senate floor in which those opposed to the prevailing position constituted at least one-third of those voting. Party unity is based on all voting members of a party casting their vote the same way, excluding abstentions.

Sources: Virginia's Legislative Information System and VPAP analysis.