(CNN) With Herman Cain's nomination for the Fed, uh, flagging and Stephen Moore's nomination for the Fed in only slightly better shape, Senate Majority Leader Mitch McConnell sent a very clear message to President Donald Trump on Thursday: Stop picking problematic nominees and asking us to confirm them.

Asked about the names in the mix to succeed ousted Department of Homeland Security head Kirstjen Nielsen, McConnell said this, according to The Hill

"I've not spoken to him about any of them. I have expressed my, shall I say, lack of enthusiasm for one of them ... Ken Cuccinelli. Look I'm not going to handicap all the people that could come up. There are a number of members ... who have had some reservations about some of the names that have been mentioned."

McConnell's stated opposition to Cuccinelli is due, in large part, to the fact that the former Virginia attorney general runs the Senate Conservative Fund, a super PAC designed to promote conservative challengers and which has repeatedly clashed with McConnell in recent years. "I don't think you have to wait for the midterms for Mitch McConnell to worry about his job," Cuccinelli told ABC News following Roy Moore's 2017 primary victory over McConnell-backed candidate Luther Strange in Alabama. (Moore went on to lose the general election to Democrat Doug Jones.)

So, yeah, McConnell's not a fan.

But beyond his personal animosity toward Cuccinelli, the message from McConnell to Trump is a politically astute one: These people you are nominating (or thinking about nominating) for jobs can't get confirmed.

In the case of Cuccinelli, it will come as no surprise to you that a guy who runs a high-profile super PAC aimed at beating establishment GOP senators wouldn't have a lot of fans in the Senate. (Cuccinelli is also a CNN political commentator.) And although Republicans did expand their majority in 2018, they still only control 53 seats -- which means that if four GOP senators defect, then a Trump nominee is dead in the water.

Which brings me to Herman Cain, the founder of Godfather's Pizza and 2012 GOP presidential candidate. Trump, out of the blue, proposed Cain as a candidate for one of the two open seats on the Federal Reserve. The pick drew immediate opposition, with four Republican senators now on record opposing Cain's ascension to the slot -- essentially dooming his chances.

"Herman is, you know, he's already sat on one of the Fed Boards," Trump said of Cain earlier this week. "And he's just somebody I like a lot, as to how he's doing in the process, that I don't know. You go through the process, but Herman's a great guy and I hope he does well."

And then there's Moore, Trump's nominee for the other open seat on the Federal Reserve. Since being nominated, Moore has come under fire for a past tax lien and for his closeness to Trump and his advocacy of the President's economic policies.

Of the two Fed Board nominees, Speaker Nancy Pelosi (D-Calif.) said this week : "With stiff competition, these two appointments to the Fed are the worst, ill-suited appointments that the President could come up with."

What McConnell knows -- and he is trying to make sure Trump understands -- is that every time the President makes one of these random picks for an important post and said person goes down in flames, it hurts the Senate, the President and the broader party.

Picking friends and people who have said nice things about you isn't any way to fulfill key roles in a government. McConnell knows this. Trump? Not so much.