One of three known potential Republican candidates for the U.S. Senate has made a key hiring as he explores a possible challenge to incumbent Democrat Jeanne Shaheen.WMUR has learned that attorney Bryant “Corky” Messner of Wolfeboro has hired former New Hampshire Republican Party Executive Director Todd Cheewing to help him in his efforts to determine if he will get into the race.The development comes as Messner as well as two other prospective GOP Senate candidates – former New Hampshire House Speaker William O’Brien and retired Brig. Gen. Donald Bolduc – take the necessary steps toward final decisions on whether to take on the two-term incumbent and former three-term governor, who announce in January she is seeking a third term in the Senate.Messner told WMUR in a statement Friday, “I've had helpful, insightful and encouraging conversations with Republican leaders across New Hampshire, friends, family, business associates, neighbors and many others.“Based upon these conversations and other factors, I have hired Todd Cheewing to assist me in taking further steps to explore a possible candidacy for United States Senate. I look forward to continuing these conversations over the coming weeks."It was the first comment made by Messner to the media since speculation began stirring earlier in the spring that he was interested in a possible Senate run.Cheewing also provided a statement to WMUR. “As I’ve gotten to know Corky, I see that he is exactly the sort of straight-talking, no-nonsense individual we need more of in Washington, and the sort of outsider whose real-world experience is the opposite of career politician Jeanne Shaheen,” he said. “I am excited to join his team to help him in his decision-making process.”WMUR reported more than a month ago that Messner had begun weighing a Senate run. The founder of a Colorado-based law firm, Messner is a West Point graduate and a retired U.S. Army Ranger. He has owned a home in Wolfeboro for about a dozen years and has been a resident of the Lakes Region town for about a year. Sources said that he has the financial wherewithal to put a substantial amount of his own money into a race.Messner earlier this year worked with a team of consultants, including researchers and a pollster. It is unclear if they are still being a paid by him. He has not yet filed a statement of candidacy with the Federal Election Commission but must do so when he raises or spends $5,000 toward for a campaign.WMUR has also reported Messner has been visiting with local Republican committees and attended a fundraiser for former New Hampshire House Speaker Gene Chandler. He was prominently among more than 70 hosts for a major fundraiser for Gov. Chris Sununu on May 14, the same night Sununu announced he will seek a third term as governor and not run for the Senate against Shaheen.Sources said Messner has also been to Washington for meetings with officials of the National Republican Senatorial Committee, a political organization promoting and helping to finance incumbents and challengers in what it views as competitive races in its effort to keep the GOP in the majority in the Senate.O’Brien moves closerO’Brien was the first Republican to publicly talk about an interest in challenging a Shaheen when he told WMUR in February that he had begun receiving encouragement from fellow conservatives and Republicans of various ideologies.On Friday, he took another step, telling WMUR in an interview that he is likely to run and indicated early July is the likely time frame for an announcement.O’Brien said he has been speaking with numerous activist groups throughout the state, including local GOP committees. He has been to Washington numerous times to speak with and explore fundraising opportunities among key people in the conservative network there, including well-known fiscal and tax watchdog Grover Norquist, people close to Sen. Ted Cruz, whom O’Brien endorsed in the 2016 presidential primary race, and people close to President Donald Trump. Locally, both O’Brien and Bolduc were planning to attend the Belknap Country Republican Committee’s annual Lake Winnipesaukee cruise, a major event on the GOP calendar, on Friday night.“I’m encouraged. I think there is a real opportunity to bring better representation to New Hampshire than Sen. Shaheen is providing,” O’Brien said. “And If I run, the reason will be that people are looking for someone they don’t have to guess about what they‘ll do in Washington.“I’m a proven conservative who has withstood the blow torch of political rhetoric,” he said, adding that he is “absolutely” leaning toward officially getting into the race.Bolduc: ‘A month or two’Bolduc provided WMUR’s New Hampshire Primary Source column with a statement earlier this week saying he has begun “a more serious period of gathering intelligence, assessing the potential paths to success, determining the availability of necessary resources, and planning.”He said that the expected his “due diligence to take a month or two.”Bolduc, who has been a leader in helping military veterans recognize and address struggles with post-traumatic stress disorder, has been speaking to veterans at nonpolitical events, as he did long before he considered running for office. The Stratham resident lately has been receiving informal political help from former WMUR political director Josh McElveen, a U.S. Marine Corps veteran, but there is no formal paid arrangement. “He’s a friend of mine,” McElveen said. “I got to know him through veterans’ activities and I have a ton of admiration for him. When he asked me to help it was easy to say yes. We’ll see what happens.”McElveen said the extent of his help so far has been to introduce Bolduc to people in the political community.Bolduc’s biggest challenge at the moment appears to be raising the necessary money to mount a successful run. He made that acknowledgement himself in an interview with the Laconia Sun.“My background is strong, but my question is about the money side,” he told the newspaper. “I’m not independently wealthy. I can’t just write myself a check. I’m going to need support from others.”The NRSC, meanwhile, insists that Shaheen is vulnerable despite her five successful runs for statewide office and the fact that she had already shown $1.5 million in cash on hand in her campaign account on March 31. Local Republican leaders agree.“New Hampshire will be a target state when the time comes,” Elliot Gault, the current NHGOP executive director. “It looks like we will have at least three strong candidates, and we’re going to be working hard to defeat Sen. Shaheen.”Democrats, however, are confident in the person they view as an iconic New Hampshire leader. They cite polls that show she remains popular in the state and is among the most popular members of the Senate."With Chris Sununu chickening out on a U.S. Senate race, the Republican candidates will continue to fight each other in their shadow primary, while Sen. Shaheen continues to work across the aisle to make a difference for New Hampshire families," a state Democratic Party spokesperson said.'Borderline late'A longtime Republican strategist said that although there are still 18 months until the 2020 election, the window for the challengers is wide open, and is actually beginning to close .“Not only is it not early, it’s borderline late,” said Michael Dennehy of Pinnacle Campaign Strategies, a veteran of numerous presidential and state campaigns in New Hampshire.Dennehy said that since a candidate will need to raise a minimum of $10 million to be competitive against Shaheen, “it’s not too soon to start a campaign. In fact, it’s getting to the point where it’s almost too late.“You don’t want to get to the point where you have to raise $1 million a month. That puts strain on the campaign."Dennehy also said that with the right candidate, Shaheen can be beaten in the current anti-establishment political atmosphere. “People know her and generally like her, but she’s been in politics a long time and people are truly tired of the gridlock,” Dennehy said. “And all of the talk in Washington has been about impeachment when in New Hampshire, people want to know what politicians are going to do for their families.”