The summer of an odd-numbered year may be a slow time for politics, but the same isn't true for the world of cable news. Indeed, each of the cable news giants seems to be re-imagining itself, changing personnel, and jockeying for position in the run-up to the ratings-gold 2016 campaign season.

Critics think Fox News is inching toward the center. CNN is desperate to reinvent itself. MSNBC, liberal as ever, has seen its ratings tumble. And a new cable news player could upend them all.

The biggest shake-up of the summer is at Fox News, where star Megyn Kelly will get the coveted 9 p.m. weekday slot currently occupied by conservative talker Sean Hannity. The Daily Beast's Lloyd Daily attributed this switch to "the Darwinian dynamics of demographics and ratings." Daily included this about Fox News boss Roger Ailes' guarded explanation:

Ailes reaffirmed that "Megyn has earned a better time period. She'll be in our primetime lineup."... But Ailes was downright vague about Hannity. He "is a brand that many of our viewers [italics added] love and want to see. And he's also … probably the nicest guy in the building." A case of damning with faint praise? It's doubtful that nice guys finish first in Roger Ailes' hyper-competitive world. [The Daily Beast]

Ailes insisted that "all of our stars will be back," and Hannity insisted he's "very happy" with his undisclosed future Fox role. But make no mistake, Hannity's star has clearly dimmed. His ratings have declined 35 percent since the election, due partly to his loss of credibility stemming from pre-election shows that featured a parade of GOP pundits — including Dick Morris, the worst pundit since the snake told Eve it was okay to eat the apple — who insisted Mitt Romney would surely be elected president.

And Hannity may also have to find a new home for his radio show amid reports that Cumulus Media may drop him. Conservative talker Michael Savage recently wrote, "I predict, right here, right now, that I Michael Savage and the Savage Nation is going to take over The Sean Hannity Show time slot by the end of the year. He's probably a nice guy, but his time is come and his time has gone." Savage's prediction will soon be confirmed, reports Mediaite's Matt Wilstein.

Some conservatives see Hannity's ouster as proof that Fox News is inching left. And remember: Kelly has long been one of liberals' favorite Fox News personalities, thanks to segments like this and this. So perhaps it's no wonder that Cliff Kincaid, president of a group called America's Survival, Inc. (ASI), thinks Hannity is being evicted "to make way for pro-homosexual advocate Megyn Kelly" in "another sign of the channel's left-ward drift and decline." The right-wing group is upset over Kelly's interviews in which she was tough on opponents of same-sex marriage. In May, she likened California's Proposition 8 to a ban on interracial marriage, and when conservatives blasted Fox News' Bill O'Reilly for criticizing them on the gay marriage issue, she defended him.

While plenty of conservatives may be sad to see Hannity go, it's clear that Kelly has a potentially larger appeal. She's not a totally predictable ideologue, but a lawyer who argues her case. She doesn't name-call or lash out. She's reasonable. On election night, Kelly entered the realm of living legend when she calmly decimated Republican Karl Rove's attempt to get Fox News to stop calling Ohio for Obama. In June, she received widespread mainstream and internet media attention when she obliterated Fox News commentators Erick Erickson and Lou Dobbs for their comments on women.

And yet, the liberal group Media Matters considers Kelly more "dangerous" than Hannity:

Sean Hannity is in many ways a product of an iteration of Fox News that is slowly fading away. His willingness to push any argument any Republican ever once had has eroded Hannity's credibility over time... Megyn Kelly, is a much more pernicious purveyor of political propaganda. Kelly has the unique ability to pluck misinformation and imbue it with a veneer of legitimacy that Sean Hannity has long since lost, if he ever had it at all. [Media Matters]

Of course, there's plenty of cable-news intrigue beyond Fox News. As Ad Age notes, over at the most trusted name in news, "President Jeff Zucker is trying to make CNN a must-watch even when the news is slow." The cable network is bringing back Crossfire, which ran from 1982 to 2005, and Wolf Blitzer and Anderson Cooper are getting new shows. CNN's July ratings zoomed due to its live George Zimmerman trial coverage, then returned back to Earth.

CNN is caught in a pincer, trying to carve out an identity as a traditional, fact-based alternative to two ideological channels while jumping on ratings-winning stories. That's not an easy balancing act.

Meanwhile, MSNBC has seen its ratings plummet in the 8 p.m. slot since it booted Ed Schultz in favor of fourth-place Chris Hayes. Indeed, MSNBC has finished in last place in the ratings for several months running. It remains to be seen whether a new Friday show featuring actor Alec Baldwin can possibly help...

And there's a wild card: Al Jazeera America will launch its cable network on Tuesday. In McLean's, former CNN reporter Ali Veshi, who has joined Al Jazeera, promises the new network will follow the non-partisan, fact-based BBC model:

I think we have created a world in which extreme views push out moderate views... We are going to put the resources behind commercializing real news. We are going to track those people who are NPR listeners, who watch BBC America. They exist. And we're going after them with real resources. The reason that dumbed-down news has prevailed is because there's a lot of money in producing it. And it's ubiquitous. [McLean's]

How will that impact the ratings war and influence the other networks? Stay tuned.