ABC News’ Rick Klein reports: In an interview broadcast on “Good Morning America” today, ABC’s Robin Roberts gave President Obama several chances to draw a line in the sand on the public option and declare that a bill without one would be vetoed. He didn’t bite. And from all indications going into tonight’s high-stakes speech, it appears that President Obama is going to continue to tend middle ground. ABC’s Jake Tapper reports that the president will — as he has in the past — declare that his preference is for a public option, but add that he’s amenable to other ideas that control costs by competing with private insurers. This is likely to prompt a new round of hand-wringing on the left, where anxiety is growing over the president’s commitment to the public option, as well as fresh critiques from those who are urging the president to finally stake out solid ground. “I have to say that this is one of the most frustrating moments I’ve had with the administration,” Air America host Ana Marie Cox told me and David Chalian today on ABCNews.com’s “Top Line.” “He’s made the same arguments over and over and basically we’re at a legislative stand still.” Yet this might be one of those cases where the savvier political stand is the one that straddles the issue. Conversations with several stakeholders involved in the health care talks point toward a political reality that hasn’t changed much for weeks — one that puts a premium on maximum flexibility for the White House, even at this late stage. The House, as Speaker Nancy Pelosi has promised repeatedly, appears likely to pass a bill that includes a public option. The Senate, as anyone who can count votes realizes, is exceedingly unlikely to do the same. An Obama veto threat at this stage wouldn’t change any of those dynamics, said Darcy Burner, executive director of the American Progressive Caucus Policy Foundation, a liberal group that strongly supports a public option. “I don’t know that the president needs to issue a veto threat,” said Burner, who was a Democratic candidate for Congress from Washington State in 2006 and 2008. “He has clearly stated that we need to have a public option. All the indications are he’ll reiterate his support for it as the best available method. That’s the message that certainly we’re hoping to hear.” As we’ve known from the start, the final talks will take place in a House-Senate conference committee, where negotiations are likely to center on such middle-ground concepts as co-ops and trigger mechanisms. Just as a veto threat might be counter-productive, acknowledging that the public option isn’t likely to be part of a final bill would deflate enthusiasm on the left. The Progressive Change Campaign Committee is organizing former Obama campaign workers and volunteers to remind the White House of how important the public option is to them. So even as this debate has stretched longer than the president ever wanted it to, there’s still months left in the debate. The top officials of the National Coalition on Health Care made that point in an e-mail message to members and affiliated organizations today. “On a few occasions over the next several months, the President will have to channel Ted Kennedy’s oft stated maxim, ‘do not let the perfect be the enemy of the good. But with four months to go in 2009, health care reform that would massively improve the health and finances of every American family is eminently achievable,” wrote Dr. Henry E. Simmons and Ralph G. Neas, the group’s president and the group’s CEO, respectively.