GOP presidential candidates clashed over immigration, government spending and how to handle Russia's Vladimir Putin during Tuesday night's debate. As the night got heated, the audience got involved: here are the must-watch moments. (Ashleigh Joplin and Rebecca Schatz/Fox Business Network)

The eight top Republican presidential candidates gathered for the fourth debate of the 2016 campaign Tuesday night in Milwaukee. It was a more understated affair than the last GOP debate sponsored by CNBC but still managed to yield some bests and worsts.

Here are my winners and losers from the night that was:

Winners

* Marco Rubio: Rubio's line about welders making more money than philosophy majors will be quoted all over the place in the post-debate analysis. (And, no, it wasn't totally accurate.)  Rubio knocked it out of the park when debating military spending and the right role for America in the world with Rand Paul. He got a meatball of a question when asked  by the moderators about Hillary Clinton's résumé as compared with his own; he, unsurprisingly, answered it well and easily. Time and time again, he oozed knowledge while appearing entirely relaxed. One nit to pick with Rubio: He can — and did at times Tuesday night — come across as slightly too rehearsed, the student reciting things back to the teacher from memory but without actually understanding what any of it means.

* Ted Cruz: For the second straight debate, the senator from Texas shone under the bright lights. His line about the tax code having more words than the Bible was a good and memorable one. His repeated denunciations of Washington's "crony" culture will leave a lot of Republican heads nodding in agreement. Cruz proved Tuesday night that of the "outsider" candidates, he is the one best equipped to carry their message going forward.

* Ben Carson: In the first three debates, I watched in wonder as Carson's numbers kept moving up after what I perceived to be nearly nonexistent performances. But Carson — from his first answer on Tuesday night — was more energetic (that's a pretty low bar given Carson's past performances) and more dialed in than I had seen him. He was helped by a moderator question on his past exaggerations/inaccuracies regarding his life story that would give the term "softball" a bad name. And by the fact that none of his rivals seemed interested in taking the fight to him on the issue of the inconsistencies of his recounting of the past. Carson was, as usual, very shaky on foreign policy and wasn't much better on regulatory reform. But he did more than enough to keep himself at or near the top of the GOP field.

* Carly Fiorina: Like Cruz and Rubio, Fiorina proved something Tuesday night that we already knew: She's an able debater. She inserted herself into a variety of discussions — foreign policy, taxes — where she left a positive mark. It also helped that the audience in the room in Milwaukee seemed very much on her side. I still think Fiorina, like Rubio, can come across as too rote at times.

* Rand Paul: The senator from Kentucky (finally) found ways to get his voice heard in a debate. The problem for him is that he's almost certainly too far down in polling — and in the money chase — for it to matter much. Still, Paul found a platform to voice his unique views on foreign and fiscal policy, and, at this stage of his candidacy, that amounts to a win.

Losers

* Donald Trump: Trump, as he has in each of the first four debates, stood center stage in Milwaukee on Tuesday night. But for the two-plus hours that the debate ran, Trump felt ancillary to the conversation. When he did get time to speak, he simply repeated his now-familiar lines — we don't win anymore, I have a great company, etc. — and little else. His answers on foreign policy were not good. His random attack on Fiorina — "why does she keep interrupting everybody?" — earned him boos from the crowd (and helped her). Trump just didn't seem all that interested in being there. It likely won't affect his poll numbers, since nothing seems to. But that doesn't change the fact he was off his game.

* John Kasich: The Ohio governor came out with a strategy to install himself right in the center of the debate. To do that, he interrupted, cajoled and pouted his way through it. His positions on immigration and on Wall Street banks won't win him any support from the GOP base (he got booed for his Wall Street answer). But it wasn't really about policy. Kasich seemed peevish, short-tempered and anything but presidential.

* Jeb Bush: Look, the former Florida governor wasn't bad in this debate. In fact, he was far better than the lifeless showing he put in last month. But he wasn't good enough. Jeb's first answer — pledging to repeal all of Obama's executive orders — was forceful and quite good. But as the debate wore on, Bush repeatedly missed chances to jump into conversations — a long back-and-forth involving multiple candidates over taxes jumps to mind — and when he did speak he was somewhat halting and awkward. The Bush people readily acknowledge that debating is not his strong suit. And I readily acknowledge that being a good debater doesn't guarantee victory. But Bush just isn't comfortable on the debate stage — and it shows.

* Anecdotes: Virtually every candidate took a question about broad fiscal policy and turned it into a heartwarming/heart-wrenching tale of "Jim and Aileen Jones from random city in random state." I know candidates and their staffs believe these anecdotes bolster the idea that they are out meeting regular people and not sitting in the halls of Washington — wherever those are — opining on stuff. But the anecdotes come across more often than not as trite and cliched rather than revealing and powerful. Let's just stop doing it! Okay? Good. It's a deal.

* Debate format: The Fox Business moderators went out of their way to make clear that they, unlike the unmentioned but ever-present CNBC moderators, would be sticking to substantive economic issues in the debate. Then they went out of their way to praise themselves for doing so. Fine. But the debate was largely lifeless throughout, and the lack of candidate exchanges — whether because of the rules of the debate or a simple unwillingness to engage — meant that many of the answers offered were straight from oft-repeated talking points. I don't think that serves the voters' interests — at all.