Haley Stevens

Rep. Haley Stevens says the campaign ad people have been roasting online isn't some put-on political persona ... it's pure Michigan.

TMZ DC caught up with the Michigan Senate candidate Tuesday night on Capitol Hill and asked about her now-viral "stick it to 'em" moment.

Our intrepid producer Jacob wanted to know why she decided to embrace the viral mockery instead of running from it ... and she tells us it's because she's "authentically Michigan."

Rep. Stevens explains ... she's a reflection of her constituents back home.

The campaign ad featured an amped-up Stevens promising to fight for Michiganders with "a little bit of joy, a little bit of enthusiasm, a little bit of energy, and a little bit of stick it to 'em" ... before declaring, "That's the Michigan way."