Barack Obama, Hank Williams, Jr., George W. Bush and Kanye West (WENN.COM, AFP, photos)

Hail to the Chief is clearly not in Hank Williams Jr.'s repertoire. Not this year, anyway.

The right-wing country-rocker -- who makes no secret of his dislike for U.S. President Barack Obama and once likened him to Hitler -- continued to bash the commander-in-chief during a gig at the Iowa State Fair last week, saying "we've got a Muslim president who hates farming, hates the military, hates the U.S. and we hate him!"

There's more where that came from. With the campaign heading into the home stretch, musicians on both sides are out to rock the vote. Some are informed -- like Rage Against the Machine's Tom Morello, who spurned VP wannabe Paul Ryan's love by noting "he is the embodiment of the machine that our music has been raging against." Some are silly -- like new wavers Devo, whose upcoming song Don't Roof Rack Me, Bro! is an ode to Mitt Romney's dog and his vacation from hell. And some are just plain disturbing -- like Megadeth's Dave Mustaine, who claims Obama has been "trying to pass a gun ban, so he's staging all of these murders (in) Aurora, Colo. ... and now the beautiful people at the Sikh temple." Even Ted Nugent couldn't top that.

Of course, Obama isn't the first president to face the music. Here's how some of his recent predecessors fared:

George W. Bush (2001 - 2009)

Thanks to 9/11 and the ensuing wars in Afghanistan and Iraq, Republican right-winger Dubya was just as polarizing as Obama, inspiring no shortage of protest songs and onstage rants.

ENEMIES LIST:

Kanye West blurted "George Bush doesn't care about black people" during a Katrina telethon. Dixie Chicks told a London audience "we're ashamed the President of the United States is from Texas." Let's Impeach the President, Neil Young urged on 2006's Living With War. Pearl Jam sneered in Bushleaguer that he was "born on third, thinks he got a triple." Even popster Pink pointed out Bush had "come a long way from whiskey and cocaine" in Dear Mr. President.

STRANGE BEDFELLOWS:

Amid the Kanye kerfuffle, 50 Cent took Bush's side, saying: "He incredible. A gangsta. I wanna "¦ shake his hand and tell him how much of me I see in him."

Bill Clinton (1993 - 2001)

Slick Willie and his infamous bimbo eruptions may have been the motherlode for late-night comedians, but remarkably, his eight-year term didn't inspire much in the way of memorable music.

ENEMIES LIST:

Rap-metal outfit Stuck Mojo targeted Clinton on their 1998 song Crooked Figurehead in dope rhymes like, "Your platform's weak, plus you're a thief, you need to be impeached."

STRANGE BEDFELLOWS:

Schizophrenic cult singer Wesley Willis, whose tune Bill Clinton gushed: "A lot of people across the U.S. work for you ... I like you a lot and I will award you." Then again, Willis also wrote songs about Johnny Depp, Alanis Morissette and Arnold Schwarzenegger.

George H.W. Bush (1989 - 1993)

Read my lips: Despite launching the Gulf War against Saddam Hussein, the first President Bush didn't stir up quite the same level of vitriol during his one term in office.

ENEMIES LIST:

Al Jourgensen of Ministry led a one-man crusade against Bush, sampling him on songs like N.W.O. (Jourgensen also thrashed Dubya during his term, admitting "the Bushes are kind of my muse"). Neil Young and Bad Religion also weighed in, mocking Bush's "1,000 points of light" campaign on Rockin' in the Free World and and Heaven is Falling.

STRANGE BEDFELLOWS:

Randy Travis sang Point of Light. Then again, the way things have been going for Travis lately, Bush might prefer to forget that.

Ronald Reagan (1981 - 1989)

Reaganomics, the Iran-Contra Affair and his arms race with the Russians helped make the jellybean-loving former actor public enemy no. 1 of the burgeoning hardcore-punk movement.

ENEMIES LIST:

Scores of bands like Dead Kennedys (We've Got a Bigger Problem Now), D.O.A. (F---ed Up Ronnie), DRI (Reaganomics); The Ramones (Bonzo Goes to Bitburg) and Minutemen (If Reagan Played Disco). Also piling on: Violent Femmes (Old Mother Reagan), The Damned (Bad Time for Bonzo) and Heaven 17 (We Don't Need This Fascist Groove Thang).

STRANGE BEDFELLOWS:

While his bandmates blasted Reagan in song for laying a wreath at an SS cemetery, guitarist Johnny Ramone later called Reagan "the best president of my lifetime."

Richard Nixon (1969 - 1974)

The modern era of presidential-protest rock more or less begins with Tricky Dick, who was driven from office by his nefarious antics during the Vietnam War and Watergate.

ENEMIES LIST:

Pretty much everybody, though one of the most significant moments came in May 1970, when Neil Young penned Ohio in the wake of the Kent State shootings. John Lennon later referenced the "short-haired yellow-bellied sons of Tricky Dicky" in Gimme Some Truth. Other memorable cuts includes Country Joe's Tricky Dick ("the genuine plastic man") and The Honey Drippers' Let's Impeach the President. Even Canuck Andy Kim got in the act with Tricia Tell Your Daddy, suggesting Nixon's daughter remind him "he's everybody's daddy."

STRANGE BEDFELLOWS:

Elvis showed up at the White House in 1970 to volunteer his services -- and score a federal drug agent badge. And former R.E.M. guitarist Peter Buck just named his new band Richard M. Nixon, so maybe there's hope for Dick yet.