Helms was a race-baiting arch-conservative from an arguably race-baiting, arch-conservative place - central North Carolina. (He was born less than 20 miles from where my fat ass now sits.)
However, Helms - especially early in his career - was arguably (yeah there's that word again) more conservative than the state he represented. In 1972 NC was controlled top to bottom by the Democratic Party, and there was a notable history of fair-minded progressive populism here. So how come we kept sending "Senator No" to DC?
He was, believe it or not, an astonishingly effective advocate for his constituents. He staffed his local offices with very professional can-do types and he made sure nothing was ever left hanging. If your Aunt Martha was having trouble with the SSA, or Grandpa John was getting shafted by the VA, a call to Senator Helms' office always - always - got results, often the same day. And it didn't matter one bit that Aunt Martha was the local chairperson of the Rainbow Coalition or that Gramps was a fundraiser for Walter Mondale.
He quickly became literally legendary in the state for cutting through federal red tape, getting roads and bridges built after years of foot-dragging, etc.
In short, a lot of people voted for the man not because of his hard-line stances on national issues, but in spite of them.
{Insert amusing quotation here}
Apparently not loved by all his former constituents.