Singer Loomis Butchers National Anthem at Live Event, Begs for Do-Over

Step aside, Fergie ... up-and-coming singer Loomis is the latest person to totally butcher the National Anthem, and the flub is super toe-curling, to say the least.

As you can see, the singer starts off strong at the Free and Equal Elections Presidential Debate on Thursday ... but quickly goes off-key, losing her cool and begging into the mic, "I f***ed it up, I f***ed it up. Can I go back, can I go back please?"

As if that weren't enough, a cameraman chimes in to let her know she’s live -- and she’s horrified, trying to soldier on ... but her cracking voice gets worse.

She’s clearly mortified, admitting mid-song, "I got too nervous!"

Meanwhile, everyone behind her is doing their best to keep a straight face, offering a pitying round of applause when she finally wraps it up.

However, she didn’t get the same sympathetic treatment online, facing a wave of backlash and ridicule on social media.

The event was held for third-party presidential candidates, including Jill Stein of the Green Party ... Chase Oliver of the Libertarian Party ... and Randall Terry of the Constitution Party.

So until the next brave soul butchers the National Anthem, it looks like this is going to be her claim to fame for a while!