Looking forward to the 2018 elections for the Chamber of Deputies, the recently-adopted Rosatellum bis allocates a total of 45 seats in Parliament to be decided by the voters of Emilia-Romagna. Seventeen of these seats will be decided by direct election within single member districts (SMDs), while the remaining 28 districts will be allocated by proportional representation (PR) to parties and coalitions meeting the vote share thresholds established by the new law (ten percent for coalitions; three percent for parties).
Given that 61 percent of seats in the Chamber of Deputies will be elected from proportional representation lists using the largest remainder method, understanding the likely outcomes of the Rosatellum’s implementation requires understanding the geography and the electoral histories of the 27 large proportional representation districts nationally. Each one of these districts will elect a designated number of representatives by PR vote, and given the varying populations and voter participation in these districts, the power of the individual voter to influence the outcome of a PR election differs across the nation’s districts. Let us turn first toward an analysis of the power that Emilia-Romagna voters will exercise at the ballot box relative to voters in other regions.
Voter power for proportional representation in Emilia-Romagna rests slightly below the national median, with 81,739 votes required per automatically allocated proportional representation seat in parliament. Solely in terms of likelihood to affect the outcome of a proportional representation race, voters in Emilia-Romagna are only 77 percent as powerful as voters in Sicilia I, the PR district with the highest voter power — while they are simultaneously 220 percent more powerful than voters in Molise.
ALLOCATION OF SEATS
Were the rules and geographies set forth in the Rosatellum applied to the results of the 2013 elections, the allocation of PR and SMD seats in Emilia-Romagna would differ considerably but heavily favor the center-left coalition and its constituent parties. In the 2013 election for the Chamber of Deputies, 1,073,180 votes were cast for center-left coalition member parties in Emilia-Romagna, which would result in the automatic allocation of 13 PR seats under the Rosatellum — two short of half of the state’s total PR seats.
The picture is very different for single-member districts, wherein the center-left coalition would have won all SMDs in Emilia-Romagna with the exception of Piacenza, where the coalition’s margin of loss would have been under one percentage point.
Several paths exist for the center-left to outperform the hypothetical scenario that results from applying 2013 election results to the Rosatellum. First, the “low-hanging fruit” is to bridge the vote deficit within the single-member district centered on Piacenza. The coalition’s margin of defeat in the district was narrow enough that a focused get-out-the-vote (GOTV) campaign dedicated to mobilizing the memberships of coalition parties could be effective in bridging the ~1,500 vote deficit.
Substantially more votes would be required for the center-left coalition to win the “next” proportional representation seat. Once again applying 2013 election results to the Rosatellum, the center-left coalition would require a 71,166 additional votes to win one more PR seat within Emilia-Romagna. In contrast, only 759 additional votes would be required to win an additional automatically-allocated seat within Lombardia-3.
Outside Emilia-Romagna, the center-left coalition would have lost thirty-two of the new single-member districts by a margin of fewer than 5,000 votes, assuming once again that results from 2013 were applied to the Rosatellum. Intensive get-out-the-vote operations and voter mobilization efforts in areas of member party strength and geographic concentration would be particularly productive.