The North Dakota Democrat quickly shot a text message to her Republican colleague: “Don’t do it.”

A move by Collins to seek the governorship would rock the Senate and the broader political landscape. In a chamber controlled by just 52 Republicans, Collins and a handful of other centrist senators can decide the fate of President Donald Trump’s agenda. And a run by Collins for governor could eventually cost the GOP one of its last congressional footholds in New England.

Collins is torn over whether to leave her prominent perch as one of the Senate’s few true moderate legislators, according to her colleagues. If Collins had made up her mind by now, said Sen. Angus King (I-Maine), “she already would have announced it.”