WASHINGTON — What appeared at first to be a quiet, procedural decision by former Vice President Mike Pence has set off a new wave of anxiety inside the Republican Party, underscoring how fragile former President Donald Trump’s hold on the broader conservative coalition has become.

The development did not come with a rally, a speech, or a social media barrage. Instead, it unfolded through understated moves that were easy to miss — until they were not. Within hours, conservative activists, donors, and strategists were parsing its meaning, while online commentary transformed what might once have been a footnote into a full-blown political drama.

For years, Mr. Pence has occupied an uneasy place in the Trump-era Republican Party: close enough to the former president to be inseparable in the public imagination, yet permanently estranged after certifying the 2020 election results despite intense pressure from Mr. Trump. Since then, their relationship has been defined less by open confrontation than by strategic distance.

That distance now appears to be widening.

According to people familiar with internal discussions, Mr. Pence’s recent move — modest in form but significant in implication — was read by many Republicans as a signal that he is no longer content to remain on the margins of the post-Trump power struggle. While his allies insist he is acting independently and deliberately, Trump advisers privately acknowledged that the shift set off alarms.

Within Mr. Trump’s orbit, the reaction was swift. Several advisers moved quickly to downplay the significance, portraying Mr. Pence as politically diminished and disconnected from the party’s base. But behind the scenes, aides and allies described a flurry of calls aimed at assessing loyalty among donors, operatives, and elected officials who once navigated easily between both camps.

“It’s not about Pence’s raw power,” said one Republican strategist familiar with the conversations. “It’s about what he represents — permission for people to move.”

Indeed, some longtime Republican figures who have remained publicly neutral since 2021 now appear to be reassessing their positions. While there has been no mass defection, subtle shifts are visible: meetings that once included Trump-aligned operatives now do not; donors who once avoided Pence-linked efforts are quietly reengaging; and conservative policy groups are recalibrating their bets.

Publicly, the party is projecting calm. Trump allies continue to insist that his dominance among Republican voters remains unchallenged, pointing to polling that shows him far ahead of any rival. Pence allies, for their part, say there is no coordinated effort to undermine the former president, only a recognition that the party’s future cannot be dictated by grievance alone.

Still, the episode highlights a deeper tension that has lingered since the end of the Trump presidency: whether loyalty to one figure is a prerequisite for influence in the Republican Party, or whether space is slowly reopening for alternative centers of power.

Political analysts caution against overstating the immediacy of any rupture. Mr. Trump retains enormous sway over the party’s base, and many elected Republicans remain wary of crossing him openly. But they also note that power in politics often shifts quietly before it shifts visibly.

“The most consequential changes don’t usually announce themselves,” said a veteran Republican consultant. “They show up first in who takes the meeting, who returns the call, and who suddenly feels safe hedging.”

Online, the moment has taken on a more dramatic cast. Viral clips, speculative commentary, and factional infighting have amplified the sense of a movement in flux, even as the concrete facts remain limited. For supporters on both sides, perception has become almost as important as reality.

Whether Mr. Pence’s move marks the beginning of a larger realignment or simply another episode in the long aftermath of the 2020 election is still unclear. What is clear is that the Republican Party remains unsettled, its internal hierarchies less fixed than they once appeared.

As one longtime party official put it, “This isn’t a coup. It’s something more subtle — and sometimes, that’s more dangerous.”