Complex sentence: Van Buren voted in favor, and despite the cover story that he had done so only in response to instructions from the New York State Legislature, most Democrats, especially Southerners, continued to oppose tariffs after 1828.
Split into simpler sentences: Van Buren voted in favor, later adopting the cover story that he had done so only in response to instructions from the New York State Legislature. Most Democrats, especially Southerners, continued to oppose tariffs after 1828.