History suggests Republicans have a midterm advantage – but they could blow it: columnist

Jeff Greenfield is a five-time Emmy-winning network television analyst and author, and he's out today without an interesting take on how the midterm elections might go down for Democrats.

Writing in Politico, Greenfield notes, "Among the most frequently cited observations about politics — along with 'it all comes down to turnout' and 'a week is a lifetime' — is this factoid about midterm elections: 'Since World War II, the party holding the White House has suffered an average loss of 26 House seats and four Senate seats.'"

"If Democrats are to survive November with their congressional majorities intact, they’re going to have to pray Republicans really step in it in a few key races," Greenfield writes. That seems entirely plausible, he says.

In past midterms, Republicans have done serious damage to themselves by nominating scandal-plagued candidates. "Most notable was the 2010 Delaware Senate race," Greenfield recalls, "where Republican candidate Mike Castle appeared to be headed for a coronation after having won 10 statewide races for governor and the at-large House seat."

WATCH: McConnell stuns reporter after he can't name one crime that would nullify 'obligation' to vote for Trump

"But with the backing of Tea Party forces, perennial candidate Christine O’Donnell beat Castle in the GOP primary. Her fall campaign, filled with charges that she had misrepresented her education and her finances, and highlighted by a comment that she had “dabbled in witchcraft,” sent her to a landslide defeat by Chris Coons. (Had Castle won that primary and that Senate seat, the Republicans would likely now control the U.S. Senate.)"

According to Greenfield, there are a number of states where Republicans are vulnerable. "This year, the possibility of Republicans nominating credibly accused abusers in Georgia and Missouri, and a TV doctor with quackish tendencies in Pennsylvania offer Democrats tempting targets in those key states. Other Democrats hope bad memories of former President Donald Trump will give them a boost."