All of this rests on federal approval, no sure thing.
The easiest way to understand the plan, though, is as a political document. Corbett is running for reelection in 2014 with wretched poll numbers, caught between Democratic foes eager to feed the narrative that he's a heartless man, and a conservative base that hates Obamacare and worries about an unaffordable burden when the federal money tapers off.
Not to mention hospitals and other business interests pushing hard for expanded Medicaid coverage.
So Corbett is walking a fine line.
"He's navigating the small spaces available to him on this issue," said Christopher Borick, a pollster and political science professor at Muhlenberg College in Allentown.
"Staring down the president could help him in conservative circles," he said. "He has to have some enthusiasm and energy on the right. That's Job One right now."
Politically speaking, the use of private insurance in the plan gives it the patina of a free-market alternative to the federal entitlement program, which Corbett called "one size fits all" and a "Washington mandate." And taking that route will bring health coverage to more Pennsylvanians, which could help Corbett appeal to swing voters in the suburbs.
Some small-government activists, however, were not sold by what appeared to be a splitting of the difference.
"It's expansion of Medicaid by another name," said Jennifer Stefano, state head of Americans for Prosperity. "You're adding a half-million new people. The [federal] money will run out, and then who will pay for it? This is another kick-the-can-down-the-road move that's going to demoralize the base."
For months, some high-ranking Republicans close to the governor have urged him to expand Medicaid, to show his compassionate side and fight perceptions of insensitivity. When he took office, Corbett faced a $4.2 billion budget deficit, and he cut into education and safety-net spending. More than 40,000 people lost health coverage when he let the adultBasic insurance program expire, and Medicaid rolls were trimmed.
At least 10 Republican governors have accepted expansion of Medicaid, designed to cover people earning up to 133 percent of the federal poverty rate. Among them are Corbett's colleagues to the east and west: Gov. Christie in New Jersey and Gov. John Kasich in Ohio.
Democrats in the legislature had some kind words for the plan - at least Corbett was moving toward more health coverage, they said - but several of the party's gubernatorial candidates swiftly slammed him for what one called a cynical election-year ploy to have it both ways. U.S. Rep. Allyson Y. Schwartz (D., Pa.), sounded more perplexed than outraged, saying Corbett's conditions, and the uncertainty of federal approval, could cause more confusion and delay.
Schwartz said: "Is this a way to look like he's trying, or a way to not make it happen?"
GOP consultant Charles Gerow, who is advising Corbett's reelection drive, said the governor had taken a "prudent and thoughtful path" consistent with his long-expressed concerns about Medicaid's ever-growing costs. "This governor does what he thinks is the right thing to do and lets the political chips fall where they will," said Gerow.
He said he did not think Corbett would suffer much political harm from his reluctance to expand coverage without conditions. "That presupposes that swing voters will be moved by that issue," Gerow said. "The compelling issues for most voters are jobs and the economy."
Thomas Fitzgerald: COMPLETE COVERAGE
Gov. Corbett announces he will accept federal Medicaid money to insure Pennsylvanians. A1.
Citing scrutiny, Florida firm says it won't help enroll Medicaid patients. B4.
Contact Thomas Fitzgerald at 215-854-2718 or email@example.com, or follow @tomfitzgerald on Twitter. Read his blog, "The Big Tent," at www.inquirer.com/bigtent.