The more President Donald Trump antagonizes his critics, the more Republicans seem to support him, Axios co-founder Jim VandeHei told CNBC on Monday morning.

The president "feels like he's got his mojo," VandeHei said on “Squawk Box." "For all the hyperventilation ... you would think the president is going to get run out of town, yet he's at 45 percent in Gallup, the highest favorable rating he's had since the early days of his presidency,"

Trump’s overall approval rating hit 45 percent last week, matching the highest level of his presidency, which happened in the first week after his inauguration, according to Gallup’s weekly presidential approval poll.

However, on Monday afternoon, Gallup said Trump's approval rating slipped back to 41 percent. GOP support remained high at 87 percent, according to Gallup.

In a separate poll, Trump’s economic approval rating surged 6 points to 51 percent in the latest CNBC All-America Economic Survey. It was his first above 50 percent in the poll, which had a margin of error of 3.5 points.

Referring to last week's Gallup survey, VandeHei said: "The reason it's 45 percent is 90 percent of Republicans are super-enthusiastic about what the president is doing. ... I would say the tribal dimension of politics is getting more intense. And the president understands that. He sees in the polls that it may be working."

"There's this weird dynamic taking place: The more the president says things that outrage his critics, his critics go even more bananas, which then have the effect of making Republicans want to support Trump even more," even if they don’t like what he's doing on trade or at the border on immigration, VandeHei said.

VandeHei said the president is the most isolated he’s been since taking office. "He is definitely on his own more than any point in his presidency. He's doing the communication. He's doing the policy.”

“It's creating mass amounts of chaos internally,” but voters seem to be focusing on the strengthening economy and jobs picture and a possible nuclear deal with North Korea instead of all the noise, said VandeHei, who helped launch Axios in January 2017 after leaving Politico, which he also co-founded and turned into a political powerhouse. Axios has gained a reputation as a place for Washington-related scoops.