Tucker Carlson, the conservative pundit who joined Fox News to anchor an early-evening hour just a few weeks ago, is now being primed for even bigger things: He has been named to replace Megyn Kelly in the network’s 9 p.m. hour starting January 9. Martha MacCallum, a veteran afternoon host at the network, will move to fill the network’s 7 p.m. slot on what is seen on an interim basis.

“In less than two months, Tucker has taken cable news by storm with his spirited interviews and consistently strong performance,” said Rupert Murdoch, executive chairman of Fox News Channel and its parent organization, 21st Century Fox, in a prepared statement. “Viewers have overwhelmingly responded to the show and we look forward to him being a part of Fox News’ powerful primetime line-up.” NBCUniversal announced Tuesday that it had hired Kelly to lead new programs set for daytime and Sunday evenings.

The selection of Carlson to fill Kelly’s slot – one of the most-watched on cable, let alone in cable news – suggests the network will work to bolster what has worked for years in its primetime schedule, namely featuring programming and personalities with a decidedly conservative bent. Executives at Fox News have been encouraged by Carlson’s appeal to younger demographics. Since joining the outlet in November to take over a slot that had been vacated by Greta Van Susteren, Carlson’s appeal among viewers between 25 and 54 and 18 and 49 has been noticeable. “Tucker Carlson Tonight,” which will also be the title of Carlson’s 9 p.m. show, finished December as the number two cable news program among adults between 25 and 54, the demographic most coveted by advertisers, Only Fox News’ “The O’Reilly Factor,” performed better, according to data from Nielsen.

That is a break from what might have been expected from Fox News in recent weeks. Speculation around Megyn Kelly position at the network held that the younger Murdochs wanted her to stay because they saw her as a chance to speak to a rising generation of Republicans, people who valued diversity of gender and culture. Carlson appears to have some youth appeal, but would seem less likely to press Republicans as hard as Kelly, who rose to fame by lobbing pointed questions at everyone from Karl Rove to Dick Cheney.

Carlson is no stranger to the cable-news wars. He has inhabited roosts on both MSNBC and CNN. He anchored “Tucker” on the former between 2005 and 2008, and spent five years co-hosting “The Spin Room” and “Crossfire” on the latter.  He joined Fox News Channel in 2009 as a political contributor and was named co-host of the weekend edition of “Fox & Friends.” He has also had a career in print journalism, working at the conservative journal Policy Review and the Arkansas Democrat-Gazette and The Weekly Standard.  In 2010, Carlson founded The Daily Caller, a conservative news site.  He remains a passive owner, but no longer serves as the website’s editor-in-chief.

MacCallum, a veteran of NBC News and CNBC, will take over 7 p.m. with a new program called “The First 100 Days.” The show will chronicle the beginning of the new administration and run through President-elect Trump’s first 100 days in office, with a decision about the time slot to be made at a later date. MacCallum will also co-anchor the network’s Inauguration Day coverage on Friday, January 20th alongside Chief Political Anchor Bret Baier. MacCallum recently signed a multi-year deal to remain with Fox News, the network said Thursday.  “For the last 12 years, our viewers have trusted her reporting and we are pleased she will be part of our primetime line-up for the first 100 days of the new presidency,” Murdoch said in his statement.