There are few more thankless jobs in politics than giving the main State of the Union response for the opposition party. Rarely if ever does doing so benefit the political fortunes of the person providing it. Much ridicule was heaped on Florida Senator Marco Rubio for his thirsty on-camera moment in 2013 and on Louisiana Governor Bobby Jindal for coming off as amateurish in his 2009 State of the Union response.
For President Donald Trump's first State of the Union address, the task of responding fell upon former Kentucky Governor Steve Beshear. (There are other State of the Union responses but Beshear's was the primary official Democratic response.) Noah Rothman at Commentary gave Beshear a largely positive review, but for the most part the speech was criticized more than it was praised. Beshear isn't in office and may not be seeking higher office so perhaps the comments about his speech didn't hurt him much, but they also didn't help propel him or his party upward.
Perhaps the primary opposition party State of the Union response should stop being passed around from politician to politician. Instead it should be assigned to someone at a formal level, and that assignment should go to the person who holds another thankless job - the Chair of the Democratic National Committee or the Republican National Committee.
Obviously, this is something that would be done by custom and party rules not legislation, and creating such a rule would add an additional duty for the Chair of the DNC and RNC. However, it would also make it less likely that an up-and-coming elected official in either party would find their career damaged if they were asked to take one for the team and give a State of the Union response (it's probably hard to politely turn that down if offered). Further, the Chair of the DNC and RNC can legitimately claim to be a general party leader who is working to help lead the opposition to the party that holds the White House.
While some party Chairs in the past may not have performed this work capably, many could have done so. I suspect former RNC Chairs Michael Steele and Reince Priebus would have done a good job when they (and President Obama) were in office and I am confident that current DNC Chair Tom Perez would supply a good response for his party during the Trump Administration. A rule like this would make it even more of a requirement for the party Chair to be articulate and charismatic, and I don't think that is a bad thing.
Also, let's be blunt. The main purpose of the State of the Union response is to provide partisan talking points. It isn't to provide subtle observations or witty commentary. Who better to provide talking points than the head of the national committee of a political party?
The main State of the Union response is an institution in our political culture. Let's make it even more of an institution by formalizing who gives the response in a manner that makes it clear that the parties are the centerpiece of political organization. The State of the Union response should be an opportunity for the opposition party to speak its piece without having to worry about whether the response will damage one of its rising stars or give other members of the party reasons to be jealous of the person making the speech. It should become a formal job duty of the party Chaiܷr.