The divisive debate over gay marriage, which played a prominent role in 2004 campaigns but this year largely faded from view, erupted anew on Thursday as President Bush and Republicans across the country tried to use a court ruling in New Jersey to rally dispirited conservatives to the polls.

Wednesday's ruling, in which the New Jersey Supreme Court decided that gay couples are entitled to the same legal rights and financial benefits as heterosexual couples, had immediate ripple effects, especially in Senate races in some of the eight states where voters are considering constitutional amendments to ban gay marriage.

Democrats' worries are backed up by a Pew Research Center report that found that blacks were twice as likely now than they were in 2004 to say they had little or no confidence in the voting system, rising to 29 percent from 15 percent.

And more than three times as many blacks as whites (29 percent versus 8 percent) say they do not believe that their vote will be accurately tallied.

Voting experts say the disillusionment is the cumulative effect of election problems in 2000 and 2004, and a reaction to new identification and voter registration laws.