Among the first political questions he faces: Can he raise enough money?
Because although Barletta has four terms in the U.S. House and a relationship with the president, he has never had to run in a race as expensive or expansive as the one he is likely to enter.
Last year's Pennsylvania Senate race set an eye-popping record for a congressional contest, with more than $175 million in campaign spending as the state's high-priced airwaves were blitzed by Republican Sen. Pat Toomey, Democratic challenger Katie McGinty, and an army of outside groups. The two candidates combined to raise $47 million.
Barletta, who would instantly be the most established name in next year's Republican primary, has never raised more than roughly $1.3 million in any of his previous runs.
He still has more than $98,000 in campaign debts from an unsuccessful 2002 run for Congress, including part of a $78,000 loan he gave his own campaign that year. He has used $55,250 in campaign contributions collected since 2013 to repay himself, public filings show, a sign of both the slow-going to retire that debt and his relatively easy reelection campaigns. (That practice is allowed, according to independent campaign finance experts).
If he's going to attract national support, he'll have to show he can come up with the multiple millions of dollars to give him a chance to compete in a state that requires advertising in the Philadelphia and Pittsburgh media markets, Democratic and Republican operatives both said.
His early results, they added, could set the tone for whether more money flows to Barletta, or if donors decide they're better off investing in other key races.
"For a lot of political organizations, political leaders, and other donors, they look to a candidate's fund-raising capabilities as a sign of viability," said Mike Mikus, a top aide to McGinty last year. "The more you raise, the more viable you're perceived to be."
Barletta begins the race with about $513,000 in his campaign fund. Meanwhile, one of his rivals for the Republican nomination, Philadelphia-area businessman Jeff Bartos, has compiled $1 million — though half of that amount came from his own pocket in the form of a loan. None of the other seven GOP candidates have raised more than $39,000, except for one, Haverford businessman Paul Addis, who crossed that mark by loaning his campaign $100,000.
Casey had $5.6 million in the bank as of June 30, the date of his most recent campaign filings.
Barletta allies say he'll have plenty of backing, financial and otherwise — potentially from the president himself, who nicknamed Barletta and fellow Pennsylvania supporter, Rep. Tom Marino, "thunder and lightning." The congressman was one of Trump's most prominent backers in the state and has long campaigned on the same anti-illegal immigration platform that fueled much of the president's support. Big-spending political groups have "very strongly" encouraged Barletta to run, said John Brabender, one of his top political consultants.
Brabender, who said to expect an announcement "very, very shortly," said the race's national dimensions will drive donations to the challenger, especially given Barletta's staunch support for Trump and Casey's opposition to the administration.
"Contributors from all over the country that understand that this will impact the balance in the Senate, that this will be a referendum on the agenda of Donald Trump," Brabender said.
Jon Anzur, a Barletta spokesman, added in an email that conversations about a potential run have made it "clear that Congressman Barletta has overwhelming grassroots and financial support."
A similar dynamic played out last year in reverse: though Toomey, the incumbent Republican, far out-raised McGinty — who had never held elected office — independent Democratic groups poured in enough money to keep the overall spending fairly even.
Still, McGinty's former aide, Mikus, cautioned that there's no guarantee such groups will spend money in Pennsylvania the way they did last year, because the 2018 race may not be a top tier contest.
Even though Trump won Pennsylvania, Republicans might have more inviting targets in more conservative states with Democratic senators such as West Virginia, North Dakota, Missouri, and Indiana. A recent CNN ranking of the top Senate races placed Pennsylvania's outside the top 10.
GOP challengers will have to show that they can make the Pennsylvania race as competitive as those in other states, political veterans said.
"Money follows opportunity in politics," said Mark Dion, who managed Toomey's unsuccessful 2004 run for Senate. "If Barletta gets in and shows that he's capable and can get the national Republicans to buy into what his game plan is, then money won't be an issue."
Republican state chairman Val DiGiorgio also cautioned against reading into Barletta's previous fund-raising. The Congressman from Hazleton, he noted, was running in a less expensive media market and didn't need to come up with multiple millions.
The challenge will be turning his experience running in a 705,000-person district in Northeast Pennsylvania into trying to campaign statewide — with a race that will span all 18 Congressional districts, instead of just one.
"You're basically trying to put together an organization 18 times that size and you've only got a year and a half to do it," said Dion, who helped Toomey go from Congressman to statewide candidate.
Few regular voters are likely to be paying close attention to next year's elections yet, which is why candidates tend to spend the early part of their campaigns introducing themselves to political leaders and interest groups — and raising money for the eventual spending deluge.