– Gov. John Kasich, a blunt-spoken and unorthodox Republican who bucked his party by expanding Medicaid under President Obama's health care law and says politicians must "reach out and help those who live in the shadows," announced Tuesday that he is joining his party's long list of candidates for president.

Kasich, 63, becomes the 16th prominent Republican to enter the 2016 field. As a two-term governor in a critical swing state — no candidate since John F. Kennedy in 1960 has won the White House without winning Ohio — he will be a credible candidate, although his late entry means he has catch-up work to do.

"The sun is going to rise to the zenith in America again," he told a crowd at Ohio State University in describing the nation's economic challenges. "I have decided to run for president of the United States."

A onetime chairman of the House Budget Committee who led a successful effort to balance the federal budget when Bill Clinton was president, Kasich brands himself as a common-sense Midwesterner who can work with Democrats. His chief strategist, John Weaver, calls him "a rebel who can govern." He will stress his national security credentials (he also served on the House Armed Services Committee) and spotlight what he calls his "Ohio story," of jobs and economic recovery, boasting of the $2 billion surplus his state has amassed on his watch.

"If he catches fire, he will be very, very successful and one of the finalists," said Newt Gingrich, a former House speaker, who predicts that Kasich will join Sen. Marco Rubio of Florida as "one of the two guys who talks the most about the future, and innovation, and doing things differently."

But Kasich is not nearly as well-known as other candidates; polls show about 2 percent of Republicans back him. A critical early test for Kasich, analysts say, will be whether he can raise those numbers enough to land a spot in the Aug. 6 Republican debate in Cleveland. But it may be too late; only the top 10 candidates in polling will make the cut.

Debate access may be key

"The first debate, to me, is the first primary," said Matthew Dowd, the chief strategist for George W. Bush's 2004 re-election campaign. He views Kasich — along with Gov. Scott Walker of Wisconsin, Jeb Bush, the former Florida governor, and Rubio — as the candidates who "have a real legitimate shot at winning the nomination." But, Dowd said, "He needs to get on that stage."

Kasich aides said they are not nearly as concerned with the debate as they are with the actual first primary in February, in New Hampshire, where independent-minded Republicans like the Ohio governor (and Sen. John McCain of Arizona, some of whose former advisers, including Weaver, now work for Kasich) have traditionally fared well.

Like McCain, Kasich is brusque and often combative — even his own aides describe him, euphemistically, as "impatient" — and questions about his temperament have dogged him throughout his career. Kasich has already made six trips to New Hampshire this year, and he will head there again Tuesday afternoon for several days of town hall-style meetings with voters. He will also make quick stops later in the week in South Carolina, Iowa and Michigan. The political action committee supporting his election, New Day for America, has already spent more than $2 million on television advertising in the Boston market, which reaches into New Hampshire.

Hopes for New Hampshire

"Given his record as a pretty good fiscal conservative and someone who has grown an economy in a Rust Belt state, I think he could do well in New Hampshire," said Jeb Bradley, the GOP state Senate leader.

Kasich is likely to have a much tougher time in Iowa, where some of his policy stances — including his Medicaid expansion, his embrace of Common Core educational standards and his willingness to consider a pathway to citizenship for undocumented immigrants — rankle conservatives. While Kasich often invokes his Christian faith, especially when he speaks of helping the poor, he plays down his opposition to same-sex marriage and abortion, and may have difficulty competing against social conservatives.

Kasich briefly entered the 2000 race, but quickly concluded that he could not compete against George W. Bush, whom he has said "sucked not only all the money, but all the oxygen out of the room." Kasich subsequently quit Congress to pursue a career as an investment banker and Fox News television host. But in 2010, he returned to politics, defeating an incumbent Democrat to win the governorship. He was re-elected handily, over a weak Democratic opponent, in 2014.