Battle lines were already being drawn late Monday. The Democratic Party declared slim victories in both houses, saying it will keep Italy's interests in mind during this "very delicate situation for the country." But a top official in Mr. Berlusconi's center-right coalition said he is asking the country's interior minister to call the vote a draw.
The apparent stalemate reflects the groundswell of support for former comedian Beppe Grillo's Five-Star Movement. His throw-the-rascals-out platform drew enough voters to give it nearly as many votes as Italy's mainstream coalitions—25.6% in the lower house at the latest count, making it the single largest party in that house.
Surprising, too, was the comeback of Mr. Berlusconi, whose party was in the doldrums as late as November. The 76-year-old billionaire politician's late surge is attributed largely to the media blitz in recent weeks.