The Overton Window is the range of policies which are considered respectable in mainstream political discourse... anything outside the 'window' is considered radical. Over the course of the past forty decades, with aid from the media (particularly right-wing talk radio), the Overton Window has been shifted rightward. Once unthinkable policies, such as the gutting of Social Security and Medicare, are now considered right-of-center-though-not-unreasonable postions.
Generally speaking, the Democratic Party shifted to the right, with Bill Clinton implementing 'welfare reform' in the 90s. The Republican Party, however, has shifted so far to the right that it has veered off into fascism. Still, the push continues, as Fox personalities try to paint John Bolton, of all people, as a liberal. Yeah, THAT Bolton, the war hawk of the oughts. Bolton is a far-right figure, but he's a neocon, so his brand of far-right lunacy is not in vogue right now. The real reason why Bolton is persona non grata among the Trump Cult dead-enders is because he possesses information that undermines Trump's impeachment defense and he's enough of a loose cannon that he might actually spill the beans, if only to spite his erstwhile boss.
The MAGA supporters cannot recognize nuance... they cannot see that Bolton is a righty because he's no longer playing for their team. If he bucks Trump, he must be a lefty. We don't want Bolton. He's not even a principled conservative. I don't think there are any principled conservatives anymore. Just because some roided-out blockhead on Fox claims that he's a liberal, that doesn't mean that we need to claim him. Hell, I'm not ready to forgive that Rick Wilson guy, and he's been anti-Trump from the jump.