Democratic Donors Step Up Efforts on Senate, Clinton Bids

Democratic mega-donors, including George Soros and Tom Steyer, are putting millions of dollars into efforts to put Hillary Clinton in the White House and win control of the Senate. Their investment comes as Republicans worry about not only the chances of their nominee Donald Trump, but also his effect on down-ballot races.

Yet few of the GOP's biggest donors have put major money into Trump efforts, a striking change from four years ago when Mitt Romney had more million-dollar donors on his side than did President Barack Obama. They're also...