The party that ruled Mexico for seven decades appeared to be making a historic comeback in Sunday’s midterm congressional elections, scoring big with voters for the first time since it lost the presidency in 2000.

Early returns with about 45 percent of the ballots counted showed the Institutional Revolutionary Party, or PRI, winning about 35 percent of votes for the lower house of Congress, against about 27 percent for President Felipe Calderon’s conservative National Action Party, PAN.

At the cavernous headquarters of the PRI headquarters, party leader Beatriz Paredes predicted the PRI could forge a majority in the lower house in alliance with one of the smaller parties and called the results a vindication for the much-maligned, centrist party.

President Felipe Calderon made a speech acknowledging the results, and urging the new Congress to work together to pull the country out of the worst economic downturn since the 1990s.