The Republican Party’s 2016 presidential hopefuls have been lining up Monday to honor Martin Luther King Jr. But not a single one has lifted a finger to help fix the landmark civil rights law that was among King’s greatest achievements. And some have actively worked to undermine voting rights.Jeb Bush, Rand Paul, Marco Rubio, Scott Walker, Chris Christie, John Kasich, Mike Pence, and Bobby Jindal all have sent tweets to mark Martin Luther King Day. And why not? It’s an easy for politicians of all stripes to acknowledge an American icon, and signal sensitivity to the concerns of minorities.But actually working to defend King’s legacy appears to be much harder for the GOP’s leading voices.In 2013, the Supreme Court badly weakened the Voting Rights Act (VRA), one of King’s most important accomplishments. That ruling opened the floodgates to a host of restrictive voting laws passed by southern states which had previously been required to get federal approval for their voting laws. Reams of evidence show that many of these restrictions, including voter ID laws and cuts to early voting, disproportionately affect blacks.