In a recent interview with the New York Times, Vice President JD Vance denied that there was an “intense rivalry” between him and Secretary of State Marco Rubio. And yet, reports and speculations about tensions between them continue to emerge, with the Rubio camp allegedly spreading rumours that Vance was thinking about pulling out of the presidential campaign before it even starts

In response, perhaps, during the past two weeks, the vice president has stepped out of his routine public persona that usually avoids controversy to make bold statements critical of Israel. Rubio, on the other hand, has continued to hold the party line of unconditional support for Israel. While Vance has led efforts to negotiate a peace deal with Iran, which have rattled Israel, Rubio has spearheaded efforts to pressure the Lebanese government into an agreement on Israel’s terms.

By becoming the face of Republican scepticism of Israel and clashing with his likely presidential election rival Rubio, Vance appears to be charting his own way to the presidency – one that distances the vice president from what increasingly seem to be unpopular foreign policy positions.

Rubio, until recently, had been on the upswing, assigned ever-more important responsibilities by Trump. He has been a leading voice within the administration for a hawkish approach that has encompassed military action from Venezuela to Iran, outweighing the counsel of the more isolationist Vance.

When it comes to Israel, Rubio has made a point of being as public and proactive as possible in his support for that country and its prime minister, Benjamin Netanyahu, supporting his appeal for the US to enter the war with Iran, and even going so far as to put his name on determinations leveraging claims of national security threats to deport foreign students critical of Israel.

While the bulk of his public statements have been directed at the Netanyahu government, it is hard not to read some of Vance’s recent comments as being directly responsive to Rubio’s actions not only abroad, but at home as well.

As Vance put it, “…pro-Israel people in the United States make two critical mistakes. One, on the one hand, is not delineating between America’s interest and Israeli interests because they’re not the same. But the second is always conflating criticism of a particular government with Jew hatred, because if everything is Jew hatred, then nothing is Jew hatred.”

But, if Vance is creating space between himself and Rubio (including, apparently, by eschewing the increasingly weaponised terminology of “antisemitism”), it must also be the case that there is a political case for his doing so. That case has yet to be tested on the Republican side, where the political elites well beyond Rubio continue to move in lockstep with Israel’s Netanyahu.

But Vance, as ever, is reading the base. The same polls that show an absolute collapse of Democratic grassroots support for Israel also show an unmistakable weakening of that support in the Republican base, with one recent survey finding that 57 percent of Republicans under 50 now hold negative views of Israel.

Despite the inability of Republican elected officials to rally support behind their criticism of Israel (neither of the two most visible examples, Representatives Marjorie Taylor Greene and Thomas Massie will re-enter Congress next year), the demand signal for more frank conversation has propelled right-wing commenters like Tucker Carlson and Candace Owens to ever-greater prominence. Looking into the social media landscape, Republican questioning of the Israel relationship – particularly under the banner question of whether it represents “America First” or “Israel First,” is inescapable.

Which is not to say it will be an easy path. As sitting vice president, Vance must defer to Trump; while the latter is currently frustrated with Netanyahu, there are no guarantees that the relationship will not warm up between now and 2028 – or that if Israel elects a new leader this autumn, that that person would not be able to rebuild much of Israel’s political capital in Washington.

And similarly, if Vance’s stance on Israel helps him capture the “America First” – which is no easy task given the cohesion within that movement of the Christian Zionist camp that remains strongly pro-Israel – he may then have to contend with a Democratic competitor who seizes the Israel-sceptic mantle more credibly.

Or not. It is still early, but the favoured nominee on the Democratic side appears to be California Governor Gavin Newsom, whose few forays into commentary on Palestine and Israel have quickly been walked back to appease the pro-Israel backers of the party establishment. Indeed, the Democrats will have their own complicated, and likely ugly, battle to fight when it comes to Israel.

What does appear certain, however, is that Israel will be a wedge issue in the upcoming election – and in the wake of the failed Iran war and increasingly unpopular attacks on free speech, both greatly driven by the government of Israel or its aligned lobbies, there is an opening here that Vance, given his competition with Rubio, would have been foolish to ignore.

So is Vance’s public criticism of Israel – and pro-Israel voices within his own party genuine, or calculated? As Vance put it in his book Hillbilly Elegy, “I don’t believe in epiphanies. I don’t believe in transformative moments, as transformation is harder than a moment. I’ve seen far too many people awash in a genuine desire to change only to lose their mettle when they realised just how difficult change actually is.”

Until now, little is harder in Republican politics than to go against the prevailing dogma on Israel. And while Vance has long demonstrated what might be termed isolationist tendencies, there is no reason to think that his recent comments represent an epiphany. Rather, like any politician, he is reading the tea leaves, and sensing an opportunity on the back of a change that is filtering across American public opinion.

Vance may not be committed to driving that change. But he may be smart enough to ride it.

The views expressed in this article are the author’s own and do not necessarily reflect Al Jazeera’s editorial policy.