House Speaker Paul D. Ryan (R-Wis.) gives a presentation about a Republican plan to repeal the Affordable Care Act and replace it with the American Health Care Act on Capitol Hill in Washington on March 8. (Michael Reynolds/EPA)

On Thursday, a crucial House committee barely passed the Republican alternative to the Affordable Care Act, a.k.a. Obamacare. By a slim 19-to-17 majority, the House Budget Committee advanced the American Health Care Act (AHCA), but all of the Democrats on the committee, as well as three Republicans, voted against it.

This vote is expected to be only one step in a very difficult process to pass the AHCA, which has sparked opposition among conservative House Republicans, some senators and numerous interest groups. Indeed, according to one key forecast, the introduction of the AHCA hasn’t done anything to increase the chances of repealing Obamacare. In fact, it may have reduced those chances.

As I’ve discussed previously, The Monkey Cage and Good Judgment have been running a forecasting tournament for Trump’s first 100 days in office. One of the questions we’ve asked is whether Obamacare’s individual mandate — the requirement to buy health insurance — will be repealed by the end of the 100 days (April 30).

To date, more than 900 forecasters have weighed in. And they are increasingly pessimistic about the chance of a quick repeal of the individual mandate:

They estimate only a 20 percent chance of repeal by April 30 — down from 35 percent a month ago. What’s particularly remarkable is that the probability has dropped even since the introduction of the AHCA. In other words, the legislation intended to repeal key parts of Obamacare has made the repeal of Obamacare less likely.

Some of the forecasters’ comments illuminate the key challenges facing the GOP:

* Trump desperately needs to be seen as keeping his promises and Ryan needs to show his effectiveness as a leader. Countering this is the desperate need of Republican members of Congress to get reelected in 2018 or 2020, and the present bill includes outstanding ammunition for Democrats to use against them.

* I think it works for the benefit of all in Congress to delay a vote until after the midterm election. Republicans can have their cake and eat it, too, shifting blame onto “obstructionist” Democrats, and Democrats can look tough by voting against every unpopular/expensive aspect of any proposal.

* Artificial deadlines on complicated issues are useful for pushing things along but difficult to achieve in practice.

* Congress goes into recess after April 7 and only comes back on April 24. Very unlikely that such a controversial, impactful bill makes it through both houses in just the 36 days that Congress will actually be active before April 30.

Of course, the GOP’s efforts to replace Obamacare may ultimately come to fruition after April 30. But right now, there’s only an outside chance that they will achieve this goal as quickly as they had hoped.