SAN SALVADOR (Reuters) - Salvadorans went to the polls on Sunday to vote in legislative and municipal elections that could give a broad victory to President Nayib Bukele’s party, consolidating his overhaul of traditional politics. Opinion polls show that Bukele’s party, New Ideas, could win more than half of the mayoral positions, and enough seats to hold at least a simple majority in Congress. A two-thirds majority in Congress would let the party appoint high-level government officials, such as the attorney general and five of the 15 Supreme Court justices. Bukele, a 39-year-old publicist and city mayor, took office in 2019 promising to root out corruption and upend the two-party politics - led by the Nationalist Republican Alliance and the Farabundo Marti National Liberation Front - that has dominated since the end of the civil war in 1992. Despite garnering popularity by providing economic support during the pandemic and curbing homicides, Bukele has clashed with both the legislature and the Supreme Court, and rights groups say he has shown authoritarian tendencies. Wilson Sandoval, coordinator of El Salvador’s Anticorruption Legal Advisory Center, said it would be important to maintain a counterweight to the executive branch. Voting Bukele would essentially take away an entity that can control the executive, Sandoval said, and so “we are giving them a blank check so they can do whatever they want.” Bukele has said his rivals are fearful because his policies threaten their privileges. Polls opened at 7 a.m. (1300 GMT) and are slated to close at 5 p.m. (2300 GMT), with voters set to vote for 84 lawmakers and 262 mayors.