The Italian proportional representation system of 2005 automatically boosts the largest coalition's representation in the lower house of parliament to 340 seats (about 54%), and a similar super-assignment system at the regional level succeeded in providing the center-right with 174 seats (about 55%) in the Senate. The center-left obtained 239 seats in the lower house and 130 seats in the Senate. The scale of the center-right's majority in the Senate came as a great surprise in contrast to predictions of a tight or hung chamber. Opponents of the 2005 proportional representation law had claimed it would inherently produce unworkably small majorities in the Senate, and the previously strident calls for a new electoral law will now likely be deferred. In the absence of a defection by the Northern League (such as brought down the first Berlusconi government in 1994), the current parliament is likely to be stable and last its entire five year mandate.
With the elimination of the The Left - The Rainbow from the legislature, and the absorption of the other successor parties to the Italian Communist Party into the Democratic Party, this will be the first Italian legislature since World War II to contain no self-identified Communists. This is a remarkable transformation in a country which as recently as the 1980s had the largest non-ruling Communist Party in Europe. Since the Italian Greens chose to align themselves with the far left, they have also been eliminated from the legislature, making Italy one of the few European countries where the Greens have no representation.
For the Democratic Party, the strategy of this election was to merge the left-of-center into a single party. Walter Veltroni refused to form a coalition with the far left parties in the interest of longer term party development. His strategy was partly successful — he eliminated competition from the far left — but despite this the new party's share of the vote improved only slightly from its predecessor's performance in the 2006 election, gaining about 2%.
The Northern League (with its small Southern Italian allies the Movement for Autonomy and Alliance for the South) achieved the greatest gains in the election, doubling its share of the vote from about 4.5% to 9%. People of Freedom is dependent on the Northern League for its majority. This will give the League leverage within the centre-right coalition to advance its agenda of greater regional autonomy in Italy, and its opposition to mass immigration and any electoral changes designed to further weaken small parties.
The new Union of the Centre party (formed primarily from the Union of Christian and Centre Democrats) failed to achieve any breakthrough as a centrist third force, achieving about 5.5% of the vote, similar to its predecessors' 2006 performance.
The significant losers in the election were the far left parties, which fell from about 10% in total in the last election to about 5% in total, and lacking a unified coalition failed to obtain any seats in either house. The largest far left grouping, The Left - The Rainbow, obtained only about 3% of the vote, below the 4% threshold required for seats in the Chamber of Deputies. Its leader Fausto Bertinotti stepped down immediately after the election.
A new attempt at unification on the far right, The Right - Tricolor Flame party, achieved some success at over 2% of the vote, but also failed to reach the 4% threshold. The far right faction of Alessandra Mussolini had joined the People of Freedom rather than The Right.
Despite the return to proportional representation in the much-criticized 2005 election law, Italy took a further step in the 2008 elections toward a reduction of parties in parliament. But the strength of the Northern League, the continuing relevance of the Union of the Centre for some former Christian Democrats, the failure of the Democratic Party to absorb Italy of Values, and the possibility of a return to parliament by the far left in a future general leftward electoral shift, leave the question open of whether Italy will end up with the American-style two-party system that the main parties on the center-left and center-right appear to hope for. After the results were in, Pier Ferdinando Casini, leader of the Center Union described the developing system as not the American model, but the German model, where despite two large blocks, several smaller parties remain significant and sometimes essential to coalitions.
Following the calling of the election, Veltroni stated his party will not make any alliance in either Chamber, choosing instead to run alone with its own platform, and challenged Berlusconi to do likewise with his Forza Italia party. The main four left-wing parties not part of the PD decided to contest the election together under the banner of The Left – The Rainbow. On February 8, Berlusconi announced Forza Italia and Gianfranco Fini's National Alliance will run together under the common symbol of the People of Freedom party, being regionally allied with Lega Nord.
On February 13, Veltroni announced to have reached an agreement with the Italy of Values, led by Antonio Di Pietro, which agreed for an electoral alliance with the Democratic Party, accepting also to join the Democratic Party parliamentary groups after the election. On February 21 the Italian Radicals announced an agreement with the Democratic Party, accepting to present themselves in list with the latter, under the agreement they will have nine MPs elected in the Parliament, and appointment of Emma Bonino as Minister in case of victory.
Though Berlusconi and Veltroni were in opposite parties, they allegedly represent such similar policies that they were dubbed "Veltrusconi". Both candidates supported big tax cuts and generous spending programs.
Union of Christian and Centre Democrats was invited to support Berlusconi, but refused and decided to run on its own instead. White Rose originally planned to run alone with Bruno Tabacci as their PM candidate, but shortly before the filing deadline, they decided to form joint lists with the UDC.
The following lists ran in the election: