Mark Sanford says he should decide by around Labor Day if he’s going to mount what he has conceded would be a "long-shot” GOP primary bid against President Trump.

The former South Carolina governor and congressman announced last month that he would take around 30 days to test the waters before deciding whether to pursue the Republican presidential nomination.

“I gave myself a month and I’m running up on that deadline,” Sanford said Wednesday as he sat down for an interview with Fox News in New Hampshire, which holds the first presidential primary in the race for the White House.

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The trip was Sanford’s first to one of the early-voting states in the primary and caucus nominating calendar (other than his home state - which holds the first southern primary) as he mulls whether to run for the presidency or maybe form a think tank devoted to fiscal conservatism.

“People are politically aware here,” Sanford said. “More than any other state out there … this is a state where you can get a grassroots opinion real fast on a good idea, bad idea, go, no-go.”

One way or another, the aim of the longtime deficit hawk is to make the explosion of federal spending and a ballooning national debt a conversation in the presidential campaign.

“I think we need to have a conversation as Republicans about what it means to be a Republican,” Sanford explained. “One of the cornerstones to the Republican Party historically was, do we spend beyond our means? Do we believe in some level of financial sanity? And that seems to have gone out of the window of late.”

Sanford warned that “we’re about to drive the train off the tracks on debt, spending and accumulating deficits. And if we don’t all speak up, as Americans and as Republicans we’re going to pay the price.”

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Pointing to plans with hefty price tags being proposed by the two dozen Democrats running for the White House, Sanford said “there’s something wrong with a robust debate taking place on the Democratic side where it’s simply a debate of more versus more versus more versus more, with nobody worried about who’s going to pay for it -- and no debate taking place on the Republican side.”

Sanford, a Trump critic, criticized the president for failing to take action to curb the debt.

“It’s a problem that he hasn’t used the microphone to talk about how profound this challenge is and how it’s going to hurt every one of us if we don’t do something about it,” Sanford argued. “He’s ruled out action on the very things that drive our debt and spending. It’s irresponsible.”

Sanford’s visit came one day before Trump is to hold his first campaign rally in New Hampshire – it's a key general-election battleground state – since the eve of the 2016 election.

Trump enjoys strong support among Granite State Republicans. The latest evidence: a new poll released this week from the University of New Hampshire showing Trump with an 82 percent approval score among Republicans.

Asked if he believes he can pull off a primary upset – or if he would get in just to spotlight fiscal conservatism – Sanford said "you try to do both. Your immediate goal is, can you have an impact? Can you help shape the debate? Can you have some degree of educational impact? And, your second, longer-term goal of the process is, can you win?”

But he once again downplayed his chances, emphasizing “I think you have to acknowledge up front that it’s a long shot.”

Sanford spent his day sitting down for a few select media interviews – and meeting with Republican veterans of the state’s presidential primary. Among them were former state party former state attorney general Tom Rath, a top adviser to then-Ohio Gov. John Kasich’s 2016 presidential campaign, and former state GOP chair Fergus Cullen, one of the leaders of the “Never-Trump” movement in New Hampshire.

There’s already a Republican challenging Trump in the primaries – former Massachusetts Gov. Bill Weld. He’s been making near-weekly trips to New Hampshire since February and officially launched his bid in April. But he’s failed – to date – to make a dent in the polls.

Asked how he could succeed where Weld hasn’t, Sanford answered, “That would be the test of time.”

Weld, as the former governor of a neighboring state, has some name recognition in New Hampshire. If Sanford’s known at all in New Hampshire, it’s for the "Appalachian Trail."

That’s a reference to Sanford’s original excuse for a weeklong disappearance in June 2009. It was later revealed that Sanford was out of the country, having an affair with an Argentinian woman. The episode ended his marriage and derailed the political career of the popular two-term governor, who was considered an early leading contender for the 2012 GOP presidential nomination.

But politics is full of second chances, and the former governor won back his old congressional seat in a 2013 special election. He won reelection in 2014 and 2016. Still, Sanford, a vocal Trump critic, was targeted by the president in his 2018 reelection bid and lost a primary challenge to a pro-Trump candidate.

Asked if his possible primary challenge against the president was revenge for his 2018 loss, Sanford said no.

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But, he did take aim again at Trump over the president’s demeanor.

“For all the credits and plusses the president may have, he’s got serious demerits with regard to tone,” Sanford charged. “And you cannot play the role of schoolyard bully and expect people to follow you. Leadership fundamentally at times is not about division and how we find contrast points, but it’s about inclusion and finding ways to work together.”