He can deny it all he wants, writes Mike Allen. What’s he supposed to say, “Sure, I’d love to be the nominee without having lifted a finger to campaign”?

One of the nation’s best-wired Republicans, with an enviable prediction record for this cycle, sees a 60 percent chance of a convention deadlock and a 90 percent chance that delegates turn to Ryan — ergo, a 54 percent chance that Ryan, who’ll start the third week of July as chairman of the Republican National Convention, will end it as the nominee.

“He’s the most conservative, least establishment member of the establishment,” the Republican source said. “That’s what you need to be.”

Ryan, who’s more calculating and ambitious than he lets on, is running the same playbook he did to become speaker: saying he doesn’t want it, that it won’t happen. In both cases, the maximum leverage is to not want it — and to be begged to do it. He and his staff are trying to be as Shermanesque as it gets. Ryan repeated his lack of interest Monday morning in an interview from Israel with radio host Hugh Hewitt.

That’s just one source but Karl Rove did speculate about a “fresh face” last week and Ryan’s the most obvious choice if that happens. Only a very few potential nominees are both so well known that they wouldn’t need to spend four months introducing themselves to the public and so familiar with how a national campaign works that they wouldn’t be at sea trying to manage it. Romney’s the most obvious example but he’s widely disliked and has the stink of loser about him after 2012. Ryan, the former VP nominee, doesn’t quite have that same smell. In a “normal” primary year, had the race deadlocked between, say, Marco Rubio and Scott Walker, Ryan would be an obvious compromise choice.

But this isn’t a normal year. NBC reports this morning that, as everyone expected, the Trump and Cruz campaigns are planning to keep John Kasich off the ballot at the convention by writing their own version of Rule 40, the rule that requires a candidate to have won a majority of delegates in eight states in order to have his name placed in nomination. Trump and Cruz should have enough loyalists between them on the Rules Committee to form a majority, which can then impose any rule it wants. NBC notes that someone like Kasich could, in theory, convince a majority of eight different state delegations to pledge their support to him in writing on the second ballot, which would satisfy Rule 40, but that maneuver can be blocked with a simple tweak — simply rewrite the rule so that anyone who’s failed to meet the eight-state threshold on the first ballot can’t qualify on later ballots. That is to say, Trump and Cruz have the motive and the means to bar anyone else from being nominated — and if they can do that to Kasich, why wouldn’t they do it to Ryan? Both campaigns are hard at work right now trying to get their own delegates elected in state after state; even if Reince Priebus and the party’s leadership want to preserve the option of a dark-horse candidate being nominated on later ballots in Cleveland, I’m not sure how they can do it if Trump’s and Cruz’s delegates are opposed. I think Ryan fans are SOL.

And really, why would delegates who favor Trump or Cruz ever support Ryan as a compromise choice? Trump is a protectionist and has sworn up and down that he won’t touch entitlements; Ryan is a free-trader and the most outspoken entitlement-reformer in the party. Cruz’s fans loathe the “RINOs” in charge of the party in Congress and detest poor dealmaking with Democrats; Ryan’s the Speaker of the House and was savaged by the right for his 2014 budget deal with Patty Murray. A rare common thread between Trump and Cruz supporters is adamant opposition to illegal immigration; Ryan is notorious among for his willingness to work with Democrats on amnesty. Benjy Sarlin’s right about this:

Sketch me a scenario where Trump and Cruz delegates descend on Cleveland for a populist duel to the death in balloting and somehow end up steering around to Paul Ryan on the fourth ballot. Assuming the possibility of a dark-horse candidate hasn’t been foreclosed by the rules, isn’t it more likely we’d end up with someone like Rick Perry who has some border cred and some populist appeal? It can’t be overstated how absurd it would seem, after more than a year of populism dominating the primaries, for the guy who was “next in line” all along to be handed the nomination at the convention by establishmentarians after he didn’t even run. It would risk wrecking the party almost as surely as nominating Trump would. And really, why would Ryan even want it? If he could emerge from the convention with the party unified behind him, that would be one thing. As it is, with Trumpers deserting the GOP en masse after the nomination is “stolen” from him and Cruz fans enraged that Cruz’s tireless work to stop Trump was rewarded by having the nomination “stolen” from him too, the GOP would lie in pieces. Ryan would end up as a sacrificial lamb for Hillary, especially once she went to work on his record on entitlements. (I’d say there’s a nonzero chance that some Trump fans would cross over and support her against Ryan, partly due to entitlement fears and partly out of sheer spite.) How is this a good outcome for anyone?