Here's a contemporary Tex Mex Polka which is VERY different Italian and German polkas on the Audya. Notice the bass drum does not play quarter notes throughout. The TX Mex polka bass drum is more sparse and sometimes syncopated. Also the fills in Tejano music are more aggressive than the European polkas. Sort of a rock drummers interpretation of polka.
Here's some more banda. Notice that a the drums do not play throughout. Also a standard drum kit is not used. It more of an old fashioned marching band percussion section. Tuba is used instead of a bass guitar.
Here's some Norteña (polkas from Northern Mexico) Hear how totally different it is from the Tex-Mex(Tejano) polka? The Northern Mexican style polka is much closer to the European polkas. Still the drums and bass are a bit more driving.