Having a famous – or notorious – crossover from the opposing party speak at your party’s national convention is a time-honored tradition, one that former Democratic Rep. Artur Davis of Alabama will be continuing Tuesday night when he addresses the Republican convention in Tampa.
Despite being an established ritual, it’s one that still angers some people in the former party of the “turncoat” speaker.
Davis’s former Democratic colleagues in the Congressional Black Caucus released a letter Tuesday in which they accused him not only of “transparent opportunism” but of “nakedly personal and political calculation” and “simmering anguish” over having lost the Democratic nomination for governor of Alabama.

They noted that Davis, while a Democratic House member in 2009, had voted for the Obama stimulus bill and for the Dodd-Frank financial reform bill, stances putting him at odds with almost all Republicans.
The most famous crossover was Sen. Joe Lieberman of Connecticut, the 2000 Democratic vice presidential candidate who went to St. Paul, Minn., to speak on behalf of his friend, Republican nominee Sen. John McCain. Prior to that convention, Lieberman was even widely reported to have been in contention to be McCain’s running mate.
A recurring theme of such crossover speakers is their disenchantment with -- and sometimes bitterness -- toward their former party. In one form or another, these crossover speakers are echoing Ronald Reagan’s remark, “I didn’t leave the Democratic Party. It left me.”
Four years ago, there were Lieberman counterparts – albeit less famous – on the Democratic side.
Jim Leach, a 15-term Republican House member from Iowa who’d been defeated in the 2006 election, endorsed Obama at the Democratic convention in Denver.
Although Leach said he was “proud of my (Republican) party’s contributions to American history” he praised the “good judgment of good people in this good party, in nominating a transcending candidate,” who will “be a truly great president.”
Leach, one of only six House Republicans to vote in 2002 against the resolution authorizing President Bush to use military force against Iraq, said in Denver that “the party of military responsibility has taken us to war with a country that did not attack us.”
Obama later appointed Leach to be chairman of the National Endowment for the Humanities.
Another Republican who appeared at the Democratic convention to show his support for Obama was former Reagan administration Justice Department official Doug Kmiec.
He was still fuming about the way the Mike Huckabee campaign had attacked the man Kmiec supported for the GOP nomination in 2008, Mitt Romney.
Kmiec told me in Denver he had “been greatly impressed by Sen. Obama’s understanding of faith” and slammed Republicans for “using faith as a way of winning elections, creating fear and animosity in evangelicals and Catholics that ‘the Democrats hate you….’ That kind of fear –mongering has become a (Karl) Rove-ian trademark.”
Obama later appointed Kmiec ambassador to Malta.
The most dramatic crossover speaker at a recent convention was Zell Miller, former Democratic senator from Georgia, who delivered a scathing attack on his former Senate colleague, John Kerry, at the 2004 Republican convention in New York.
(In 2005, Bush appointed Miller to the American Battle Monuments Commission.)
“Listing all the weapon systems that Sen. Kerry tried his best to shut down sounds like an auctioneer selling off our national security,” he added.
“This is the man who wants to be the Commander in Chief of our U.S. Armed Forces? U.S. forces armed with what -- spitballs?”
On Tuesday it’ll be Davis’s turn to fire some spitballs at Obama.
