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A new poll has revealed that more than two-thirds (67 percent) of Americans support same-sex marriage.

The results from a poll published by Gallup on Wednesday mark the highest level of support the firm has ever recorded in more than 20 years of asking Americans about their views on the issue.

Gallup – a research-based consultant company, known for its opinion polls worldwide – first surveyed Americans on the same-sex union in 1996. Back then, just 27 per cent of those queried supported gay marriage.

The firm’s recorded support of gay marriage has increased by three percent annually for the past three years.

The poll also revealed a staunch divide between the views of Democrats and Republicans.

The data showed that 83 percent of those who classed themselves as Democrats said they support legally recognised same-sex marriage – compared to less than half (44 percent) of Republic respondents.

Meanwhile, just over seven in 10 (71 percent) of independents said they were in favour of legally recognised same-sex marriage.

Gallup said that the increased support for gay marriage could be the result of greater numbers of LGBTQ+ adults getting married in the US.

In 2017, Gallup revealed that around one in 10 LGBTQ+ adults were married to a same-sex partner.

“This means that Americans are more likely to know someone who has married a same-sex partner, and the visibility of these marriages may be playing a role in overturning some folks’ previously held opposition to their legal status,” Gallup said.

Same-sex marriage was legalised in all 50 states in the US in 2015 following a Supreme Court decision. The ruling came more than 10 years after the first state, Massachusetts, had made same-sex marriage legal.

Gallup has previously found that the number of individuals identifying as LGBTQ+ in America is increasing.

In 2017, the firm revealed that 4.5 percent of US adults classed themselves as LGBTQ+, up on 4.1 percent in 2017, and 3.5 percent in 2012 – the year Gallup started recording this data.

The increase in Americans identifying as LGBTQ+ has been driven mainly by millennials, which Gallup records as those born between 1980 and 1999.

Gallup’s data has shown that the percentage of LGBTQ+ millennials increased from 7.3 percent in 2016 to 8.1 percent in 2017 – up from 5.8 percent in 2012, when the company started researching on the issue.

Gallup collected its latest data on same-sex marriage as part of the company’s annual Values and Morals poll from 1-10 May, and surveyed 1,024 adults.