Mark Sanford, a former South Carolina governor and congressman, said he is inching closer to a bid of his own by sounding out activists in New Hampshire and other early-voting states about an insurgency focused on the ballooning deficit.

Jeff Flake, a former Arizona senator and Trump antagonist, said he has taken a flurry of recruitment calls in recent days from GOP donors rattled by signs of an economic slowdown and hungry for an alternative to Trump.

And former Ohio Gov. John Kasich will head to New Hampshire next month to "take a look at things" after experiencing "an increase" in overtures this summer, an adviser said.

The anti-Trump movement inside the Republican Party - long a political wasteland - is feeling new urgency to mount a credible opposition to Trump before it's too late.