In just eight days, Arizona Sen. John McCain has gone from having to win a primary to survive as the Republican front-runner, to having to win the next primary just to survive, period.
Roller-coaster ride? It's been more like a pendulum.
After finishing second Tuesday in the Michigan Republican primary to Mitt Romney, the former governor of Massachusetts, McCain is in the precarious position of having to win in South Carolina to have any kind of realistic hope of becoming the GOP presidential nominee.
There was a lot at stake in Michigan. A McCain victory would have kept alive his momentum coming off his win in New Hampshire and, just as important, could have effectively doomed Romney, his deep-pocketed rival.
But independent voters and Democrat crossovers — McCain's strength — failed to come out in anywhere close to the numbers of 2000, when McCain won in Michigan.
In 2000, just 48 percent of GOP primary voters were registered. The rest were independents and Democrats, with whom McCain tends to do very well. This time, registered Republicans comprised 68 percent.
Another ominous trend for Arizona's senior senator was that voters for whom the economy was the most important issue went for Romney overwhelmingly, exactly the opposite of what happened in New Hampshire.
McCain may now be regretting the "straight talk" he dispensed when he said some jobs in Michigan were never coming back. Romney pounded away on that as evidence McCain was willing to give up the many thousands displaced workers fallen victim to the decline of the auto industry. It seemed to matter little that McCain was almost probably correct.
McCain also seemed unable to offer an easily comprehensible plan for turning around Michigan's slumping economy. He spoke of eliminating wasteful federal spending, eliminating the alternative minimum tax and developing "green technologies," but those are difficult concepts for some to grasp in a state in need of urgent relief for the unemployed.
In the end, McCain and his aides blamed their loss mostly on Romney's personal ties to the state. Romney, of course, was born and raised in Michigan. His father, George, was a popular three-term governor.
"Michigan was good to its native son," McCain said in his concession speech in Charleston, S.C.
Less than a week ago, Romney suspended his TV ads in South Carolina and Florida and focused on Michigan.
He may now make at least a token effort to see whether he can parlay the Michigan victory into a good showing in South Carolina. But recent polls show Romney running fourth behind McCain, former Arkansas Gov. Mike Huckabee and former Tenn. Sen. Fred Thompson.
McCain's biggest threat in South Carolina is his good friend Huckabee.
Like McCain, Huckabee will be fighting to stay alive. He too needs to win in the Palmetto State. McCain has foresworn going negative against his pal "Huck." That pledge may prove harder to abide by now.
If McCain loses South Carolina — and remember: in the do-or-die calculus of presidential primaries even a close second can be deemed a loss — it is difficult to see how he can recover. He would surely stagger on to Florida, whose primary is Jan. 29, but it might be too late to recover from back-to-back losses.
At what was supposed to be a victory party Tuesday night, McCain said gamely, "We've gotten pretty good at doing things the hard way. … And I think we've shown them, we don't mind a fight."
He's fighting now for survival.