Former U.S. Senator John Edwards leaves the federal court house in Greensboro, North Carolina April 23, 2012. Edwards, 58, is accused of secretly soliciting more than $900,000 in illegal campaign funds from two wealthy donors to hide his pregnant mistress during his failed bid for the 2008 Democratic presidential nomination. (CHRIS KEANE/REUTERS)

As star witnesses go, Young was none too shiny; he repeatedly got flustered, annoyed the judge by mumbling, and raced through those answers that were at variance with his tell-all book. He so often made the prosecutor repeat his question that I lost track of how many times the government lawyer had to admonish his own witness: “Sir, that’s not what I asked you.’’

Still, two crucial things Young said under oath Tuesday did ring true:

His detailed description of how Edwards persuaded him to claim paternity for the child the candidate himself had fathered with Rielle Hunter was credible.

And when Young said his motivation for agreeing to do such a thing was completely opportunistic – “I wanted my friend to become president because a lot of benefits go along with that’’ — he was at his most convincing.

Prosecutors say Edwards knowingly broke the law by using illegal campaign donations to keep his mistress quiet and his ‘08 presidential chances alive.

But the defense maintains that it was Young’s idea to claim paternity, and that Young was freelancing when he solicited money from Edwards supporter Bunny Mellon. Edwards says Young bilked her -- not on his behalf, and not even for Hunter’s benefit, but to pay for the $1.5 million home Young was building. Young did not, however, come off as a likely mastermind.

There he was, he said, buying a turtle aquarium for his kids, when Edwards called on his cell and went right into stump speech mode, telling him that he needed him to claim paternity not for his own sake, but for the sake of something that was bigger than all of them, because it would allow Edwards to become president, vice president, or attorney general.

Edwards also told him that his wife Elizabeth was dying, Young said, and that he didn’t want headlines about a messy, career-ending affair to dominate the final months of her life.

But by his own account, Young did not agree out of either loyalty or sympathy for Mrs. Edwards, but because he was still hoping to cash in – though he no longer thought it likely that his one-time dream of working in embassies around the world under President Edwards was going to come true.

There were a slew of internal inconsistencies in Young’s testimony; at one point, for instance, he said Edwards didn’t want to know any of the details about the various schemes for paying off Hunter, so that if he became attorney general later, he wouldn’t have to lie.

At a number of other points, Young said Edwards had detailed knowledge of what was happening, and indeed was directing him. Of course, life is full of inconsistencies, especially amid a drama this over-the-top.

The defendant showed emotion only twice on Tuesday; when Young said Edwards wanted to keep his hands clean so he could become AG, the former senator raised his eyebrows in either astonishment or mock astonishment, and shook his head.

And when Young made a mistake in his timeline and said Hunter was pregnant before that was the case, Edwards looked triumphant, shared looks with his defense team and whispered to them.

Though Edwards made his fortune as a trial attorney juries just loved, he wisely made no attempt to charm them from the defense table, and took notes instead of angling for eye contact.

Again today, the former candidate’s parents and grown daughter Cate were seated behind him in the courtroom, and to those who’ve asked me if Cate looks like she’s there under duress: absolutely not. A lawyer herself, she’s in constant, animated conversation with her father during breaks, and with worry written all over her face, twists and tugs on her hair during testimony. Though she bears a physical resemblance to both of her parents, she’s like Elizabeth in being so obviously all in on behalf of John Edwards.

Some of Young’s stumbling statements were inadvertently helpful to his old boss: He testified that Edwards told him the money being funneled from Mellon to her decorator, to Young’s wife and then to Hunter was perfectly legal because it was a private gift, not campaign cash.

One of the most horrifying stories Young told on the stand, in terms of the risks Edwards took while running for president, concerned the very night he announced his ’08 run. After Young picked him and Hunter up for the kick-off event, the former aide said, they passed a bottle of wine back and forth between them en route.

The candidate was feeling so fearless, in fact, Young said, that he dared to bring Hunter right into the rally, where his wife and the mistress all but literally collided while one was going into the ladies’ room and the other coming out.

Years ago, Edwards told me the secret to convincing a jury. The trick, he said, is to tell them all the weaknesses in your case right up front, so that they’ll think gosh, you’re honest, and will then believe the rest of what you’re selling.

You mean, I asked, that it’s sort of like the saleswoman who tells you that Dress A does not really maximize your charms, so that when she later tells you Dress B is stunning, you believe her? Ex-actly, he said.

If that’s true, the prosecution must have scored big points with the jury on Tuesday, because they certainly led off with the weakness in their case, Andrew Young. But judging by how flummoxed he was by the lawyer for his own side, he stands a very good chance of being ripped apart by the defense.

Melinda Henneberger is Post political writer and anchors ‘She the People.’ Follow her on Twitter at @MelindaDC.