Can Congress restrict which individuals are eligible to serve as federal judges?
<p>Federal judges in the United States are appointed by the president with the advice and consent of the Senate. The constitution does not impose any restrictions on who may be appointed and confirmed as a federal judge.</p>
<p>Where the constitution prescribes limitations on eligibility for the Presidency and Congress, those limitations have been held to be exhaustive (for example, term limits cannot be imposed on Congress because doing so would be inserting eligibility requirements in addition to those in the constitution).</p>
<p>If Article III is interpreted using a similar principle, then it means that notwithstanding any law to the contrary, the President may appoint, and the Senate may confirm, any living human as a federal judge, and the conflicting provisions in the law would be unconstitutional.</p>
<ul>
<li>Is there precedent regarding this issue?</li>
<li>Have any legal experts opined about this issue?</li>
</ul>

<p>The US Congress contains a number of legal experts, and Congress has imposed statutory limits on certain federal judicial positions (<a href="https://www.law.cornell.edu/uscode/text/28/45" rel="nofollow noreferrer">age</a> and <a href="https://www.law.cornell.edu/uscode/text/28/44" rel="nofollow noreferrer">residence</a> as well as <a href="https://www.law.cornell.edu/uscode/text/28/45" rel="nofollow noreferrer">previous service</a>), so you could take that to be weak evidence that qualifications are constitutional. There doesn't seem to be any case law where a President acted otherwise.</p>

<h2>Congress can limit itself</h2>
<p><strong>But it cannot limit a future Congress or the President</strong></p>
<p>The text is:</p>
<blockquote>
<p>... and [the President] shall nominate, and by and with the Advice and Consent of the Senate, shall appoint Ambassadors, other public Ministers and Consuls, Judges of the supreme Court, and all other Officers of the United States, whose Appointments are not herein otherwise provided for, and which shall be established by Law: but the Congress may by Law vest the Appointment of such inferior Officers, as they think proper, in the President alone, in the Courts of Law, or in the Heads of Departments.</p>
</blockquote>
<p>Since the Constitution does not specify any restrictions, there are none.</p>
<p>How the President and the Congress (or either chamber alone) make their decisions is not specified so it is a matter entirely for them and is not justiciable - that is, a court cannot intervene. This contrasts with administrative government decisions where the law specifies a procedure - if that procedure is not followed a court can rule the decision invalid and order the decision maker to do it again properly. Since the Constitution is mostly silent on the <em>how</em> of Presidential and Congressional decision making there is very little scope for judicial interference.</p>
<p>That said, Congress can (has to) itself decide  on the <em>how</em> but each Congress does this for itself. The fact that many say, “we’ll do it the way the last lot did” is just economical, it’s not required.</p>

united-states us-constitution