Independent presidential candidate Robert F. Kennedy Jr. is objecting to being excluded from planned debates between Democratic incumbent Joe Biden and Republican Donald Trump, the former and perhaps future White House occupant. His exclusion really isn’t a surprise; the major political parties of the United States traditionally treat politics as a private club closed to new members. But, with the two ancient retread candidates in a tight race and Kennedy making a strong showing that could easily affect the outcome, the stakes are higher than usual this year.