The New York Times :
Republicans maintained control of the Senate on Tuesday, fending off numerous Democratic challengers who polls showed were leading going into Election Day, as incumbents were pulled along by Donald J. Trump’s unanticipated strength in several key battleground states.
Senators Ron Johnson of Wisconsin, Richard M. Burr of North Carolina and Patrick J. Toomey of Pennsylvania made late comebacks to win re-election and to help ensure Republicans retained power.
Senator Marco Rubio, Republican of Florida, who insisted a year ago that he would not seek another term and embarked on a failed race for president, defeated his Democratic challenger, Representative Patrick Murphy.
Many other incumbents fared well, even in a climate of high voter dissatisfaction with anyone who could be labeled part of the Washington establishment.
Senator Rob Portman of Ohio, a Republican who was considered highly vulnerable when the campaign began, easily won re-election, as did Senator John McCain, Republican of Arizona. Senators Roy Blunt of Missouri, Rand Paul of Kentucky, Tim Scott of South Carolina and James Lankford of Oklahoma, all Republicans, also won.
In Wisconsin, Mr. Johnson, who had been trailing badly against former Senator Russ Feingold, was aided by an enormous cash infusion from outside groups.Democrats did gain a Senate seat in Illinois with Representative Tammy Duckworth defeating Senator Mark S. Kirk, a Republican. And in Nevada, Catherine Cortez Masto defeated Representative Joe Heck, retaining the seat for Democrats held by Senator Harry Reid, who is retiring. But they lost their chances at a gain when Evan Bayh, who had served two terms each as governor and senator in the state, lost to Representative Todd Young.
Many races narrowed substantially in the closing weeks, and analysts in both parties predicted that the Senate would be closely divided no matter which party took control.
From the beginning of the election cycle, Republicans were on the defensive in the Senate, where they had far more competitive seats in play than the Democrats. In the House, gerrymandering and the Republicans’ largest majority since the 1930s seemed sure to keep the chamber in their control.
In the Senate, seven incumbent Republicans elected in the Tea Party wave of 2010 seemed particularly vulnerable, but the party had built up something of a buffer with big wins in 2014 that gave it a four-seat majority.
Republicans also benefited from the efforts of Senator Mitch McConnell of Kentucky, the majority leader, who tried to make sure that incumbents did not face the kind of challenges from the right that had bedeviled the party since 2010.
Mr. Toomey, Mr. Burr and Senators Kelly Ayotte of New Hampshire and Charles E. Grassley of Iowa all avoided seriously contested primaries, allowing many of them to run as seasoned center-right candidates as opposed to hard-line conservatives. Mr. Rubio also avoided a messy intraparty fight for his seat once he entered the race after his failed shot at the White House.
Republicans’ fear of Mr. Trump’s presidential bid lingered before the votes were tallied. Most starkly, Mr. Toomey, Republican of Pennsylvania, waited until the last possible moment to say that he voted for the Republican nominee after weeks of evading the question.
But in the end, some candidates who rejected Mr. Trump prevailed, others who abandoned him lost and those who tried to avoid the question of his candidacy did fine. Mr. Portman, who started off as a provisional underdog, began an early attack on his opponent, Ted Strickland, the former Ohio governor, over job losses during Mr. Strickland’s tenure. His no-stone-unturned campaign – which even included radio ads in Ukrainian – and a big volunteer network helped him compensate for a less robust turnout operation from the top of the ticket. The Republican Party’s task appeared to get infinitely more difficult when its voters chose Mr. Trump to head the ticket. Suddenly, the divisiveness was coming not from challengers to the incumbents but from the man running for president who railed against Washington politicians, including many of those seeking re-election.
Most Senate candidates initially remained mum about Mr. Trump’s candidacy, but they were forced, often awkwardly, to react to his many contentious statements.
Mr. McCain and Ms. Ayotte eventually broke with their party’s nominee, saying they could not support his quest for the White House. But Mr. McCain did so not after Mr. Trump insulted him personally or after Mr. Trump offended a Gold Star family, but only when Mr. McCain had obtained a comfortable lead. Ms. Ayotte rejected Mr. Trump after various tortured moments, which cost her support. Mr. Portman stuck to his position of supporting Mr. Trump while largely distancing himself from his remarks.
In Nevada, Mr. Heck, seeking the seat vacated by Mr. Reid, the Democratic leader, renounced Mr. Trump, only to incur a fierce backlash from Trump supporters. Ms. Cortez Masto, who had Mr. Reid’s strong backing, will become the nation’s first Latina senator.
Some themes of the election transcended partisanship. Mr. Blunt, Republican of Missouri, and Mr. Bayh were hit repeatedly for their ties to lobbyists. Mr. Bayh, who began his race with a double-digit lead in polls over Mr. Young, was swamped by negative ads paid for by outside political groups that painted him as out of touch with his state and too in touch with Washington’s insider culture.
The negative tenor of Mr. Trump’s campaign clearly had a significant impact in states where Democratic Party leaders failed to recruit high-wattage candidates for some winnable seats. Still, those candidates ran highly competitive races and in some cases were poised for victory.
Their Pennsylvania recruit, Katie McGinty, held a midlevel position in Bill Clinton’s White House but no major elective office. In North Carolina, former Senator Kay Hagan passed on a comeback, and Democrats settled on Deborah Ross, a little-known lawyer for the American Civil Liberties Union. One clear exception was New Hampshire, where Democrats persuaded the state’s popular governor, Maggie Hassan, to challenge Ms. Ayotte.
In Florida, Mr. Murphy was seen as a credible opponent against what started as a disorganized field of Republicans hoping to succeed Mr. Rubio. But once the incumbent jumped back in, Mr. Murphy quickly took criticism for funding his campaign with the help of his wealthy father and for padding his résumé. Democrats, disappointed with his campaign, put their resources elsewhere.
The nation’s Senate races ended in a record level of cash. “Super PACs” and other outside groups spent more than $600 million on behalf of candidates this year, the bulk of it in roughly half a dozen competitive races, according to the Federal Election Commission.
The total surpasses every biennial upward progression of outside money in races since the 2010 Supreme Court decision that determined that the government was prohibited from restricting independent expenditure by groups that can raise unlimited money in political campaigns.
