Republican presidential aspirant Donald Trump may still be sitting comfortably on top of various popularity surveys, but he is losing ground in two key demographics: churchgoers and women.

This became evident in the latest Reuters/Ipsos survey, which showed eroding support for Trump in socially conservative states like Kansas, Iowa and Nebraska.

In these same states, which are seen to play key roles during the Republican presidential nomination contest come February, Republican presidential candidate and Trump's closest rival, Ben Carson, is gaining ground.

Based on the Reuters/Ipsos poll, Carson's support among regular churchgoers leaped from 22 percent in September to 32 percent this November, the highest of any Republican candidate.

Trump's support from religious voters meanwhile declined from 26 percent to 22 percent.

Ford O'Connell, a Republican strategist, said Trump's declining support among evangelical voters may open the door for Carson to eventually grab the lead in the presidential race.

"If Carson keeps his nose clean he could win those states," O'Connell said, as quoted by Newsmax.

The change of voter preference from Trump to Carson in these states shows that the retired neurosurgeon's story is resonating strongly with churchgoers, O'Connell said.

In the same manner, Trump is bleeding support among female Republican voters, with his popularity ratings slipping from 30 percent to 25 percent.

In contrast, Carson's figures rose among Republican women voters, garnering 27 percent support this November from 19 percent in September.

Republican voter Bridget Miller, 43, from Stilwell, Kansas, for instance, said she had initially considered voting for Trump, but had switched to Carson because of the retired neurosurgeon's conservative values and stand on controversial issues.

"Carson is pro-life; he's pro-gun; he's saved baby's lives. He speaks to a lot of our values here," she told Newsmax.

Trump recently escalated his verbal attacks on Carson. Just this week, the controversial business tycoon likened his closest rival to a child molester.