Wisconsin governor and Republican presidential candidate Scott Walker appeared baffled and unable to give a quick answer when asked again last week if President Barack Obama is a Christian or not.

"You're not going to get a different answer than I said before," he told the Washington Post. "I don't know. I presume he is. But I've never asked him about that. As someone who is a believer myself, I don't presume to know someone's beliefs about whether they follow Christ or not unless I've actually talked with them."

In the end, Walker decided that he would simply believe what Obama said earlier about his faith—that he is indeed a Christian. "He's said he is, and I take him at his word," he simply said.

Walker was first asked the question about Obama's religion back in February during the National Governors' Association meeting.

"I don't know," he said then. "I've actually never talked about it or I haven't read about that. I've never asked him that. You've asked me to make statements about people that I haven't had a conversation with about that."

Obama has always said he is a Christian, even attending regular Christian church services. However, the President's faith has been a highly contested topic since there are many conspiracy theories that claim he is actually a Muslim or an atheist. At the same time, his support for same-sex marriage has been viewed by many as very un-Christian.

Questions about his religion and nationality began in 2004 when he started his campaign for the US Senate, followed by the 2008 presidential campaign. Despite winning both times, the rumours prevailed. According to a research conducted by the Pew Research Center back in 2012, 17 percent of Americans, including one-third of conservative Republicans, believe Obama is a Muslim.