To test your AJAX is working

add_action( 'wp_ajax_editCommittee', 'test_ajax_request' );
add_action( 'wp_ajax_nopriv_editCommittee', 'test_ajax_request' );
function test_ajax_request() {

    echo "Request: " . PHP_EOL;
    
    var_dump( $_REQUEST );

    exit;
}

And update your request to move the action into the data sent:

jQuery (document).ready (function($) {


    $ (".edit_tr").click (function() {


        var commitID = $ (this).attr ('id');

        // on click, hide the text
        $ ("#name_" + commitID).hide ();
        $ ("#created_" + commitID).hide ();
        $ ("#status_" + commitID).hide ();
        $ ("#disbanded_" + commitID).hide ();

        // on click, show the input fields for editing
        $ ("#name_input_" + commitID).show ();
        $ ("#created_input_" + commitID).show ();
        $ ("#status_input_" + commitID).show ();
        $ ("#disbanded_input_" + commitID).show ();

    }).change (function() {

        var commitID = $ (this).attr ('id');
        var name = $ ("#name_input_" + commitID).val ();
        var date_created = $ ("#created_input_" + commitID).val ();
        var status = $ ("#status_input_" + commitID).val ();
        var disbanded = $ ("#disbanded_input_" + commitID).val ();
        var dataString = {
            action: 'editCommittee',
            id: commitID,
            name: name,
            date_created: date_created,
            status: status,
            disbanded: disbanded
        };

        console.log (dataString);
        // can place loading image here
        
        $.ajax({
            type : "post", 
            url: "/wp-admin/admin-ajax.php",
            data: dataString, 
            error: function(xhr, status, error) {
                var err = eval ("(" + xhr.responseText + ")");
                alert (err.Message);
            },
            success: function(response) {
                $ ("#name_" + commitID).html (name);
                $ ("#created_" + commitID).html (date_created);
                $ ("#status_" + commitID).html (status);
                $ ("#disbanded_" + commitID).html (disbanded);
                console.log ("Got this from server: " + response);
                console.log ("This is what happened to data: ");
                console.dir (dataString);
            }
        });
    });

I you still don't get anything it's probably your URL. You can try to localize the admin-ajax.php URL like this answer shows: http://stackoverflow.com/a/22007593/5623301