By Patrick SvitekThe Texas TribuneTexas Republicans are increasingly debating who should be allowed to vote in their primary as the March 5 contest nears with the presidential nominee at the top of the ticket.The debate has increased in recent days as presidential candidate Nikki Haley has talked openly about targeting states like Texas that have open primaries, or primaries that are open to voters regardless of partisan affiliation. But even before the former South Carolina governor started trumpeting her strategy, GOP activists in Texas were zeroing in on limiting the state’s primary to Republicans, crafting a nonbinding ballot proposition on ...