A "rainbow wave" that lifted record numbers of LGBTQ candidates to victory in the U.S. midterms is a promising sign of growing acceptance, but tough legislative fights still lie ahead in many Republican-controlled states, rights campaigners said.

Even as Republicans gained a slim majority in the House of Representatives, the absence of the predicted "red wave" could act as a buffer against anti-LGBTQ legislation in the new Congress that will be sworn in on Jan. 3.

"The Democrats in the House and Senate have been our firewall," said Zeke Stokes, a political consultant and the former chief programs officer at the LGBTQ advocacy group GLAAD.