The act has been proposed to protect same-sex and interracial marriage rights, both of which rest on historic Supreme Court rulings which many fear could be overturned.
It would repeal the 1996 Defence of Marriage Act (DOMA), which defines marriage as between a man and woman.
Though the act was made void by 2013 and 2015 Supreme Court rulings, if these were to be overturned, it would become active again.
The proposed act would also provide legal protections for interracial marriages by prohibiting any state from denying out-of-state marriage licenses and benefits on the basis of sex, race, ethnicity or national origin, AP News reported.
With the Respect bill having already cleared the House of Representatives, more than 400 former and current Republican politicians have urged GOP senators to get behind it ahead of an expected vote this month.
A letter produced by Centreline Action and Conservatives Against Discrimination says “civil marriage is a fundamental freedom central to individual liberty and the pursuit of happiness”.
It notes “71 percent of Americans, including a majority of registered Republicans, support the freedom to marry for all Americans”.
It ends by saying: “Simply put, the Respect for Marriage Act treats all American families as each of us would want to be treated.”
Among the signatories are Barbara Bush, daughter of George W Bush; David Urban, former top adviser to Donald Trump’s 2016 presidential campaign; and Tony Fabrizio, a pollster for Trump’s 2016 campaign, the Washington Post reported.
Passing the Respect For Marriage Act has become a priority for Democrats after the Supreme Court’s decision to overturn Roe vs Wade, gutting abortion rights across the country.
When the ruling was handed down, Supreme Court justice Clarence Thomas released a concurring opinion claiming there was an an opportunity to reconsider “all of this court’s substantive due process precedent”.
This includes Obergefell v Hodges, the 2015 ruling on same-sex marriage, and others including those that legalised contraceptives.
The 1967 Supreme Court ruling in Loving v Virgina, which struck down state laws banning marriage between difference races and legalised interracial marriage, also falls into this category. Thomas himself is in an interracial marriage.
The Respect For Marriage Act has existed in various forms since 2019, and was passed by the House of Representatives in a bipartisan vote of 267 to 157 on 19 July this year.
A total of 47 Republicans joined a full-house of 220 Democrats to support the bill.
However, with the senate divided 50-50, at least 10 Republican senators must back the bill for it to become law.
According to the Washington Post, some senators have argued that the bill is unnecessary, while others have cited unjustified concerns that it would allow for polygamous marriages or infringe on relations liberties.
The newspaper reported the bill’s sponsors are working to amend the clarity of its scope, with suggested tweaks including specifying that marriage is between two people and making clear the measure does not undermine conscience or religious liberty protections.