Peel potatoes; chop into 1/2-inch or 3/4-inch chunks. Place in stockpot and fill with water about an inch above potatoes. Bring to a boil over medium-high heat and continue boiling until potatoes are fork-tender, about 10 min.
Drain potatoes; place in mixing bowl. Beat until fluffy. Add butter, sour cream, Mexican cheese, chives and bacon. Beat until incorporated and potatoes are fluffy. Check for desired texture. For creamier potatoes, beat in a little milk. (I added 1/4 cup.)