Big seat to fill. Photo: Drew Angerer/Getty Images

The hole that John McCain’s death has left in the lives of his family (and the hearts of many a Capitol Hill reporter) will be difficult to fill. His seat in the Senate is a different story.

While the nation mourns its fallen maverick (and/or, bickers on Twitter about whether he was a patriot or a jingoist; a human rights advocate, or a supporter of South African apartheid; a man who bravely resisted his party’s Trumpist turn, or who cravenly helped to birth it), operatives and elected officials are gaming out the political implications of his departure.

Here’s a quick rundown of what McCain’s death will — and will not — mean for American politics going forward.

Arizona governor Doug Ducey will make one of the most important decisions of his career.

John McCain’s last major political act was not his deciding vote against repealing Obamacare — but rather, his decision to remain in his Senate past June 1 of this year. Had McCain stepped down before that date, Arizona voters would have been able to chose his replacement in a special election this fall. This would have given Democrats an outside shot of netting two Senate pickups in Arizona, and securing control of the upper chamber.

By holding on through the summer, McCain gave governor Doug Ducey the opportunity to handpick his successor, who will not need to face voters until November 2020.

This will be a tricky decision for Ducey, who is looking to win reelection in Arizona this fall — and, reportedly, to be the GOP nominee for president in the medium-term future. Thus, one could imagine the governor opting for a “moderate” Republican, out of desire to appeal to swing voters this fall and honor McCain’s idiosyncratic example.

But all signs suggest Ducey will cruise to reelection, and personally installing a RINO in the Senate would alienate donors and activists he’ll need in a future bid for higher office. Thus, despite early rumors, it is exceedingly unlikely that Ducey will appoint Cindy McCain (whose policy views are not well known) to her husband’s seat in a caretaker capacity.

While Ducey is sure to pick a conventional Republican, it’s unclear precisely what brand of “conventional” he’ll settle on. As FiveThirtyEight’s Perry Bacon Jr. notes, “the Arizona GOP is divided between a more establishment wing (Ducey) and a more tea party one (former sheriff Joe Arpaio).” Bacon Jr. predicts that Ducey will opt to pick a “caretaker” replacement for McCain — someone who would step down in 2020, thereby allowing Republican primary voters to pick the senator’s long-term replacement — so as to avoid inflaming either wing of his state party.

But reporting from the Washington Post suggests Ducey “favors appointing someone who could hold on to the seat.” Which makes sense: Arizona is turning purple, and forfeiting the advantage of incumbency would give Democrats a better chance of capturing McCain’s old seat in 2020.

Republican sources provided the Hill with a short list of potential appointees:

Several sources also pointed to former senator Jon Kyl (R), McCain’s longtime seatmate who is now shepherding Judge Brett Kavanaugh’s nomination to the Supreme Court, and former representative John Shadegg (R), who left Congress in 2011.

Mitch McConnell’s job is about to get a bit easier.

Any of the contenders on Ducey’s short-list would (almost certainly) make it easier for McConnell to push his agenda (which is to say, far-right judges) through the Senate. With McCain sidelined, the GOP’s majority in the upper chamber has been 50-to-49 for most of this year — a margin that allows any individual Republican senator to hold business hostage to his or her idiosyncratic demands. Granted, few in McConnell’s caucus have availed themselves of this power. But some do miss votes on occasion, forcing the Majority Leader to rely on Democratic cooperation.

Now, McConnell has breathing room in the short term — and, in all probability, a much more loyal vote for the president’s agenda in the long one. If Republicans fend off the threat of a Democratic takeover this fall, they’ll return to Washington next year with a much more uniformly pro-Trump caucus (as less independent freshman senators would likely take the seats of Bob Corker, Jeff Flake, and John McCain).

Brett Kavanaugh will still probably be confirmed, while Obamacare repeal will remain dead.

McCain’s replacement will give McConnell a higher margin for error in the Kavanaugh confirmation fight. With McCain sidelined, it would only have taken a single Republican defection (plus unanimous Democratic opposition) to sink Trump’s Supreme Court pick. Now, it will take two.

But pro-choice Republicans Susan Collins and Lisa Murkowski were already giving every indication that they would rather protect Senate norms than a woman’s right to choose. And vulnerable, red-state Democrats have evinced little appetite for taking a high-profile stand against Trump right before facing the voters this fall. So, McCain’s departure is probably a moot point.

Similarly, McCain’s replacement is unlikely to cast a deciding vote in favor of repealing Obamacare. Although McCain’s opposition was decisive last summer, now that Democrat Doug Jones has one of Alabama’s Senate votes, Murkowski or Collins would have to flip to get repeal through. And there’s no sign that either has interest in reversing one of the most popular votes they’ve ever taken.

That said, if Republicans manage to keep the House — and pad their majority in the Senate — then repeal will become a real possibility next year.

Republicans will talk a bit less about human rights when justifying their desire to drop bombs on foreigners.

A news analysis from The Wall Street Journal suggests that the GOP might now accelerate its turn “away from the robust internationalism propounded by Mr. McCain toward a more limited role for the U.S. advocated by President Trump.”

But this is a bad misdescription of Trump’s actual foreign policy. After all, the president’s vision of “limited role” for the U.S. on the world stage has involved extending the longest war in American history (despite the utter absence of a coherent strategy or compelling national interest in Afghanistan); increasing the nation’s gargantuan military budget; overruling theE.U.’s right to set its own foreign policy by imposing sanctions on all European firms that do business with Iran; bombing Syria’s sovereign government multiple times without United Nations approval; and asserting (albeit, without, as of yet, exercising) America’s right to launch a preemptive war against North Korea if it does not forfeit its nuclear arsenal.

There are few signs, then, that McCain’s departure will lead the Republican Party to embrace a less interventionist approach to geopolitics. But it is plausible that his absence will accelerate a shift in how the party rationalizes the assertion of American might on the world stage. McCain framed his support for the American imperial project in missionary, universalist terms:

The United States had a responsibility to facilitate the proliferation of liberal democracy, and to prevent genocidal atrocities, the world over. McCain (and his fellow neoconservatives) might have applied these arguments selectively (tip-toeing around the authoritarianism and human rights violations of America’s allies). But their putative reverence for internationalism, and liberal democracy, nevertheless had real implications for the substance of U.S. foreign policy.

In Trump’s mercenary, mercantilist vision of American empire, the U.S. has no special investment in Europe’s well-being, or in preserving the legitimacy of (U.S.-built) international institutions. In fact, Trump’s empire barely has any use for diplomats or soft power of any kind: Even as the president jacks up America’s military budget, and expands its international commitments, he’s sought to shrink the State Department and slash foreign aid.

McCain might have been the GOP’s most prominent defender of the Cold War–era conception of America’s role on the world-stage (including its responsibility to counter the threat Russia supposedly poses to Western values). Now, he’s gone. And there’s little sign that the Republican base will be eager to elect “globalists” of his vintage in the future.