President Trump, right, confers with House Speaker Paul D. Ryan after a luncheon celebrating St. Patrick's Day on March 16. (Win McNamee/Getty Images)

The GOP's on-again, off-again health-care push is apparently stalled again.

After the bill was amended to address the concerns of the very conservative House Freedom Caucus this week, some of those members got onboard — apparently breathing new life into the effort. But then a bunch of moderate Republicans signaled their opposition Thursday, and House Majority Leader Kevin McCarthy (R-Calif.) announced late that night that there would be no vote this week.

The announcement deprived President Trump of a much-desired win before his first 100 days in office are up this weekend. But more than that, the whole situation reinforced the fundamental, intractable problem the White House and Speaker Paul D. Ryan (R-Wis.) face in getting this done — one that has never really gone away.

That problem is that this bill has critics both in the center and on the right. And most any effort to appease one side is going to come at the expense of the other.

We saw this Thursday, as even some moderate members who had supported the previous iteration of the GOP's health-care bill came out against this one. The so-called MacArthur Amendment (explained by Philip Bump here) would allow states to apply for waivers for federal rules and allow insurers to charge those with preexisting conditions more than others. It was crafted by Rep. Tom MacArthur, a moderate from New Jersey, in consultation with the Freedom Caucus — in hopes of appealing to both the Freedom Caucus and moderates.

It didn't work on the latter count. Rep. Adam Kinzinger (R-Ill.), who supported the previous version of the American Health Care Act, announced that he opposed it. The same was true of Rep. Mario Diaz-Balart (R-Fla.). Rep. Ryan Costello (R-Pa.), who had been a free agent last time, came out against it.

“I’m not seeing how this new language, this proposed new language, does anything but make the bill worse, not better,” Diaz-Balart told HuffPost, adding: “Every time I read it, there are more red flags that keep popping up.”

HuffPost's Matt Fuller, who has been doing yeoman's work on a whip count, currently has 38 GOP members as either against the bill (17), leaning against it (10) or undecided (11). The GOP can only afford 22 defections.

And Diaz-Balart's comments are instructive. The MacArthur Amendment clearly moved the bill to the right in hopes of appealing to free-market conservatives, but it did nothing to address concerns about rising premiums for older Americans and the millions who the Congressional Budget Office say would be off their insurance under the AHCA. It actually created more problems for a moderate crowd that is concerned about having to answer for Obamacare's benefits being ripped from their constituents.

And perhaps the bill's biggest hurdle remains in the Senate, where a number of senators have said they simply won't vote for anything that reduces the insurance rate. They can only lose two GOP senators and pass the bill, which the CBO says would leave 24 million off insurance by 2026.

The changes this week did nothing to address that reality. And any future changes are going to run into this very same problem: appealing to one wing of the party at the expense of the other. Winning over those skeptical moderate senators is only going to inflame the Freedom Caucus, and vice versa.

Trump has shown that not all of American politics exists on a two-dimensional spectrum. But within the GOP right now, this issue does. And it's proving a nearly impossible needle to thread.