Mayor Carlo DeMaria Jr. has emerged as a favorite in his bid for reelection after he registered a strong first-place showing in last Tuesday’s preliminary election. The three-term mayor picked up 3,130 votes to 1,624 for Ward 5 Alderman Robert Van Campen and 607 for Ward 1 Alderwoman Millie Cardello. A total of 5,400, or 28.4 percent, of the city’s 19,017 registered voters turned out at the polls. DeMaria and Van Campen, who is the city solicitor in Melrose, will vie in the Nov. 5 city election. The race comes as Everett is in the midst of a high-stakes competition to bring a casino to the city. Adding interest to the race is that the city’s mayoral term shifts to four years with the start of the new term in January, as a result of a charter change approved by voters in 2011. Also as a result of that change, the City Council will switch from a bicameral structure to a one-branch body.