(Bloomberg) -- Construction-related stocks tumbled as the close U.S. elections stirred fears that political gridlock would block an increase in infrastructure spending.Vulcan Materials Co., Martin Marietta Materials Inc. and United Rentals Inc. were among the 10 worst performers in the S&P 500 Index in late-morning trading. The outlook for more investment in public works is “probably the key casualty” of the vote, Jefferies analyst Stephen Volkmann said in a note to clients.“While Republicans have also spoken supportively about infrastructure, funding remains a key issue,” he said in the report.