Holman Jenkins, columnist and member of The Wall Street Journal's editorial board, said Wednesday Republican Donald Trump still isn't acting presidential, and he wonders whether the real estate billionaire even wants the job.

"He's not taking this seriously. He's not spending his money like he promised to. He has not broadened his appeal like he's said he was going to. He's not toned down his rhetoric like we hoped he would," Jenkins told CNBC's "Squawk Box" in an interview. "Does he really want to be president, I ask myself."

Jenkins, who's been rather critical of Trump in his writings, said on CNBC he may still vote for Trump. "Thank God we don't have to decide until November. Trump can show us a lot more between now and then."

"I like the idea of a guy who wants to go to Washington and radically change direction on taxes and regulation," Jenkins said, but questioned whether Trump would be able to deliver on his promises of lower taxes and a friendlier regulatory environment for businesses.

"A lot of what Trump says, I don't like. But I don't take his ideas that seriously," Jenkins added, while taking Trump to task on his remarks on Monday, following the weekend terror attack at the gay nightclub Pulse in Orlando that resulted in 50 deaths, including the American-born gunman Omar Mateen.

"The Orlando speech he gave ... was kind of lame. All he wanted to do was relive his greatest hit on keeping Muslims out of America. A lot of people expected more from him," Jenkins said.