(J. Scott Applewhite/AP Photo)

Most Americans in a new ABC News/Washington Post poll support the recent U.S. Supreme Court action allowing gay marriages to go forward in several states - including a bare majority in the 11 states in which such marriages have begun in the past week and a half.

Overall, 56 percent of Americans support the court's action, while 38 percent oppose it - exactly matching opinions on whether or not gay marriage should be legal, asked in an ABC/Post poll in June. These results reflect the public's dramatic shift in support of gay marriage the past decade.

See PDF with full results, charts and tables here.

By declining to hear several appeals, the high court cleared the way for gay marriage in five states - Indiana, Oklahoma, Utah, Virginia and Wisconsin. Three others in the same jurisdictions followed suit (Colorado, North Carolina and West Virginia), and gay marriage bans in three additional states, Idaho, Nevada and Alaska, were rejected by other courts in the past week.

In the 19 states (and Washington, D.C.) that had previously legalized gay marriage, the court's decision is especially popular: Sixty-six percent support the decision, with 30 percent opposed. Support is sharply lower, but still 51 percent, in the 11 states that have allowed gay marriage since the Supreme Court's action, vs. 42 percent opposed. (The rest are undecided.)

Americans divide similarly, by 48-44 percent, support-oppose, on the court's action in the 20 remaining states in which gay marriage remains illegal.

More than half of Americans have supported legalizing gay marriage steadily in ABC/Post polls since March 2011, a sea change from earlier attitudes. Support was as low as 32 percent (in a poll among registered voters) a decade ago.

At the same time, the issue remains divisive. This poll, produced for ABC by Langer Research Associates, finds that seven in 10 strong conservatives, nearly two-thirds of Republicans and 72 percent of evangelical white Protestants oppose the court action.

Sentiment on both sides, moreover, is intense - seven in 10 Americans have strong feelings on the subject, including 38 percent who "strongly" support the court action and 32 percent who strongly oppose it. Only 18 and 6 percent "somewhat" support or oppose the action, respectively.

GROUPS - Support includes more than seven in 10 college graduates and adults under 40, and more than six in 10 Catholics and non-evangelical Protestants alike, falling sharply among their counterparts.

Eight in 10 liberals are in favor, as are six in 10 moderates, vs. just a third of conservatives. And support ranges from 72 percent of Democrats and 63 percent of independents to 25 percent of Republicans. Indeed, in a separate question, 49 percent of independents say their opinion of gay marriage is closer to the Democratic Party's; just 23 percent say they're closer to the GOP on the issue. Largely as a result, Americans overall are 17 points more likely to side with the Democratic Party over the GOP on the issue of gay marriage, 48 vs. 31 percent.

Partisan differences explain some of the variability in state groupings. In the 19 states where gay marriage was previously legal, Democrats outnumber Republicans by 15 points, 35 to 20 percent. In the 11 states where such marriages began this week, fewer are Democrats - 26 percent - vs. 29 percent Republicans. It's a 29-25 percent split in the 20 remaining states where gay marriage remains illegal.

METHODOLOGY - This ABC News/Washington Post poll was conducted by telephone Oct. 9-12, 2014, in English and Spanish, among a random national sample of 1,006 adults, including landline and cell-phone-only respondents. Results have a margin of sampling error of 3.5 points, including design effect.

The survey was produced for ABC News by Langer Research Associates of New York, N.Y., with sampling, data collection and tabulation by Abt-SRBI of New York, N.Y.