According to the exit polls, Protestants voted 65% YES on Prop 8, and Catholics voted 64% YES on Prop 8.
I see no support for that statement in the linked article.
Exit poll data showed seven in 10 black voters and more than half of Latino voters backed the ballot initiative, while whites and Asians were split.
A different analysis also would question your assertion:
A Times database analysis of Proposition 8 voting in Los Angeles County shows some clear geographic divides over the issue of banning gay marriage. The database team produced a variety of interactive maps designed to help understand Proposition 8 balloting in L.A. and across California. Here are some highlights:
WESTSIDE: Voters rejected Proposition 8 on the Westside by a large margin. About 66% of voters in Beverly Hills voted "no," as did 78% of Santa Monica voters. In Malibu, 69% voted no. Opposition was also heavy in the hillside corridor west of downtown from Echo Park and Silver Lake to Hollywood and West Hollywood, and also in the Mid-Wilshire, Fairfax and Beverly Center areas. That strong opposition to the measure jumped over the Hollywood Hills to the affluent "south of Ventura Boulevard" crowd and even farther north.
SOLID SOUTH and EAST: Some of the strongest support for Proposition 8 was south of downtown L.A., among black and Latino voters. In Compton, 65% of voters said "yes," as did 60% in Huntington Park, 61% in Inglewood and 63% in Lynwood. Similar levels of support were evident in predominantly Latino cities to the east, including Whittier, El Monte, Baldwin Park and Pomona.
ASIAN VOTE: Several cities with large Asian American populations -- Monterey Park, Alhambra, Temple City, San Gabriel, San Marino and Cerritos -- backed the measure. (Some of these cities also have sizable Latino populations.)
ALONG THE COAST: In the South Bay, the biggest opposition was along the coast. The beach cities -- Redondo, Manhattan and Hermosa -- all voted "no" by healthy margins. But on the Palos Verdes Peninsula, all four communities approved Proposition 8 (Palos Verdes Estates, however, did so by a thin margin).
FAR WEST VALLEY: The 101 Freeway corridor generally voted no: Agoura Hills, Calabasas, Hidden Hills and Westlake Village.
City with the largest "yes" percentage: INDUSTRY, 82% (but only 18 voters)
City with the largest "no" percentage: WEST HOLLYWOOD, 86%
