The Associated Press:

With a flurry of coast-to-coast developments this week, same-sex marriage is back in the political spotlight and likely to remain there through Election Day as a half-dozen states face potentially wrenching votes on the issue.

... In all the showdown states, national advocacy groups are expected to be active on both sides. The Human Rights Campaign, for example, has promised to provide funding, strategic advice and field staff for the various campaigns supporting same-sex marriage.

On the other side, the National Organization for Marriage is vowing a multistate effort, including promises of financial support in the primaries to defeat any Republican lawmakers who support gay marriage in Washington.

Though several major national polls now show that a slight majority of Americans support same-sex marriage, National Organization for Marriage president Brian Brown predicts his side will continue its winning streak and prevail in any state referendums that are held this fall.

"There's a myth that history is on a trajectory moving toward same-sex marriage," Brown said. "There is no such momentum."