WASHINGTON – Arlen Specter's Pennsylvania two-step has left Senate Republicans even deeper in the hole – deep enough, perhaps, to accelerate the departure of Texas Sen. Kay Bailey Hutchison.

Fellow Republicans have pressured Hutchison, who would leave Washington to run for governor, to hang on as long as possible, to avert the possibility of a costly – and risky – fight to hang on to a critical seat. But the math changed when Specter defected to the Democrats, putting the Senate head count at 59 Democrats, 40 Republicans.

The long-festering Minnesota recount should end in a few weeks, with the state's highest court expected to order the governor to seat Democrat Al Franken over GOP rival and former incumbent Norm Coleman.

That would give Democrats 60 votes, a filibuster-proof margin they crave. And it could give Hutchison the excuse she needs to mount an early exit so she can focus on trying to oust Gov. Rick Perry in the GOP primary next spring.

"If Norm Coleman wins, we'll be at 41. And if she left and we lost that seat, we'd be at 40," said one colleague keeping close watch on Hutchison and the larger chessboard, Texas Sen. John Cornyn. His job chairing the party's Senate campaign committee makes him responsible for electing as many Republicans as possible.

"On the other hand, you can argue that our numbers are so diminished now that one more won't have much of an effect on outcomes," he said.

It's a safe bet that Hutchison will reassess after Minnesota is settled. The calculus will involve tough personal tradeoffs.

The longer she stays on the job in Washington, the less time she has in Texas to chip away at Perry and show the flag at Rotary lunches.

On the other hand, she wants to avoid getting entangled in gnarly legislative issues before lawmakers in Austin wrap up their session in a few weeks. Staying above the fray lets her second-guess the governor after sine die, even as she maintains the national visibility she enjoys – albeit on national issues.

Is that enough?

"It may not provide her the platform to talk about purely state issues in which she is going to be engaged and which she would have to deal with, were she elected governor," Cornyn said.

More to the point, every Senate vote she casts gives Perry a chance to paint her as a creature of Washington, and a squishy conservative who can't bring home enough bacon.

Hutchison doesn't want to leave her party in a lurch, nor give up her day job and bully pulpit too soon. And she's probably loath to hand the governor a plum vacancy to fill – though, as we saw in Illinois, New York and Delaware last fall, governors don't always win friends when they get the chance to anoint a senator.

Would Perry name someone to merely keep the seat warm, or try to install someone he hopes keeps the Senate seat for the long haul? New contenders will probably emerge when the Legislature goes home, and at the moment, Republicans fear they don't have a strong enough candidate to defend the seat.

Though Republicans still dominate the state, a special election to replace Hutchison would have different dynamics that could give a Democrat a strong chance to win.

"If we get a strong candidate that can win the race, then ... concerns will be alleviated to some extent," Cornyn said.

But as the primary gets closer, Hutchison will feel a stronger and stronger tug to return full time to Texas.

"We've had a lot of conversations ... and she reads what I say, I read what she says in the paper. My conversation is, 'We cannot afford to lose your seat, so please, whatever you do, let's work together to hold it,' " Cornyn said. "She understands very clearly what the negative impact both on the country and our state would be if that seat were to change hands, and she is committed to holding it."

Todd J. Gillman is Washington bureau chief of The Dallas Morning News.

tgillman@dallasnews.com