Mike Johnson knows three things about the expiring Obamacare subsidies. First, if the House had a free vote on extending them, it would pass. Second, refusing to hold that vote could cost the GOP the control of the House. And third, if he does permit the vote, the right wing of the party will be outraged, and he could lose his job.
In short, he doesn’t have any good options. For now, he is dealing with the problem by stalling and changing the subject; in his eyes, the issue is reopening the government and eliminating the blue team’s leverage, not soaring health care premiums. In the longer run, I suspect he will decide that the GOP has other ways to win the election–gerrymandering, crime, and a hypothetically improving economy–so the safer approach is to let the premiums rise and keep the Freedom Caucus happy.