The Federal Reserve is expected to raise its benchmark interest rate on Wednesday for the first time in three years, as Fed Chair Kevin Warsh and other officials seek to demonstrate that the central bank is responding seriously to inflation. Higher borrowing costs could slow the rise in consumer prices, but they would also add pressure to an already struggling housing market, where mortgage rates have topped 7%, and weigh on consumer sentiment near record lows. The move would add to Republicans’ economic challenges ahead of the elections, alongside soaring oil prices and government borrowing costs at their highest level in two decades. Rep. Frank Lucas (R-Okla.), who chairs a House task force on monetary policy, said many Republican lawmakers have accepted that the decision is beyond their control.