Midterm elections that will serve as a referendum on President Donald Trump’s second term will begin to come to a close Tuesday as Americans, angry over high prices and an unpopular war with Iran, decide whether to drastically shift power in Washington. Democrats were cautiously optimistic about their prospects as they watched Republicans spend the campaign’s final stretch dumping tens of millions of dollars into states and districts that Trump won handily just two years ago. They are betting that discontent over Trump’s failure to deliver on his promise to tackle rising costs will depress Republican turnout and drive their own voters to the polls.