There’s an old saying in Chicago politics: Once you’re bought, stay bought.

In other words, if you are being paid to behave a certain way, don’t flip-flop.

Those who would like to think they understand our new president would do well to keep that adage in mind. For if there is one thing that President Donald Trump has proven himself not to be so far, it’s that he’s anything but predictable. Love him or hate him, he marches to his own drummer. And by the usual Washington standards, it’s a different rhythm indeed.

And just about the time you think you have him figured out, he’s likely to change course. Just ask Israel.

During the campaign trail, he promised to be Israel’s “best friend.” Translation: He would support policies and tactics favored by the current government — including expanded Jewish settlements outside current borders in East Jerusalem and the West Bank. Then last week, he said more building “may not be helpful.”

But Israel is hardly alone when it comes to wondering where the guy really stands. Many nursing home operators were positively giddy when Trump unexpectedly captured the White House in November. As a successful businessman, he was already a bit of a kindred spirit. Plus, he promised to crack down on regulatory oversight. And what skilled care operator wouldn’t want that?

There’s no doubt he’s taking on regulations and trying to make the nation’s economic climate more capitalism friendly. But even early on, we’re seeing a few chinks in the pro-business armor.

For one, the Department of Justice just announced it plans to stay focused on fraud in the skilled care sector. According to several published reports, the DOJ also plans to prosecute more operators. Those are not exactly tactics out of the GOP playbook.

Then there’s Trump’s executive order putting a new immigration ban in place. As my colleague Elizabeth Newman pointed out in her blog Friday, foreign workers play a significant role when it comes to healthcare headcounts.

So, in a sector where good help is hard to find, a core supply spigot is being turned down?

There’s no getting around the fact that Trump is a different kind of politician. Already, he’s rewriting the rules for the way a president acts or reacts.

Whether he’s ultimately going to be good or bad for the sector remains very much an open question. My guess is that he will be a bit of both.

One thing is for sure, though. When it comes to how he’s likely to behave, we’d better get comfortable with the notion of expecting the unexpected.