Black Lives Matter. #MeToo. Joe Kennedy III?

(CNN)Outraged by President Donald Trump's action in office and fueled by the #metoo and Black Lives Matters movements, Democrats' liberal base is hugely engaged and activated.

What better time than the Democratic response to Trump's first State of the Union speech on Tuesday night to capitalize on that momentum with a voice from and of those twin movements, right?
Or pick Joe Kennedy III, a white male Massachusetts Democrat and scion to one of the most famous families in American politics.
That's not to say Kennedy wasn't good; "Droolgate" aside, he delivered a solid rebuttal to Trump and cast Democrats as a credible alternative. And it's not to say Kennedy isn't a voice for the future of the party; at 37, he is widely regarded as a rising star who might someday run for president.
    It's just to say that, at first glance, he seemed like a somewhat odd pick for this moment.
    But, there are lots of extenuating circumstances that went into the Kennedy selection that show just how hard it is to find exactly the right person to deliver the SOTU response. Among them:
    1. 2020 politics: The most prominent names within the Democratic party -- Cory Booker, Kirsten Gillibrand, Elizabeth Warren, Bernie Sanders, Kamala Harris etc. -- are all actively thinking about running against Trump. They represent the diverse face that the party wants to put forward. But, to choose any one of them to deliver this very high profile address would look like that person was getting favorable treatment -- and a leg up in the 2020 jockeying. You can be sure that if, say, Gillibrand was chosen to give the Democratic Response, the political operations for Booker, Warren and Sanders would be up in arms. So, none of them wind up even getting considered.
    Coming soon

    CNN Original Series "American Dynasties: The Kennedys" premieres Sunday, March 11, at 9 p.m. ET.

    2. Fundraising: A big part of the calculation when choosing who will give the response to President's State of the union speech is how the party's donor base will respond. You need someone people know -- or someone whose name they recognize. You need to turn their frustration in watching Trump's speech into actual dollar contributed to Democratic causes and committee. Whether or not donors know the specifics of Joe Kennedy III's life, they know his last name and like it. That makes it more likely they decide to part ways with their cash.
    3. Proven performer: People, most of whom are sitting on their couch in sweats, are convinced that doing this sort of public speaking is easy. All you have to do is read the teleprompter! As we've seen in the recent past -- Marco Rubio's water grab, Bobby Jindal's unwitting "Kenneth the Page" impersonation -- it's a lot harder than it looks, even for people who make a living speaking in front of large numbers of people. Neither party wants to run the risk of a total PR disaster by plucking someone who isn't used to the bright lights of a national address. They want a proven performer; a safe pick is always better than a sorry pick.
    When you run all of the prospective Democratic response deliverers through that gauntlet, the number of choices is much more limited. Oregon Gov. Kate Brown has an interesting profile but is largely unknown nationally. Ditto Rhode Island's Gina Raimondo, who, nonetheless, would have been an intriguing pick. Virtually every Senate Democrat under 65 is running for -- or thinking about running for -- president. Aside from Nancy Pelosi, who is too divisive a figure to put in the response speaking slot, there just aren't any House members with national profiles.
    And so, the duty fell to Joe Kennedy III. He wasn't the perfect pick. But that''s because a perfect pick almost certainly didn't exist.