2016 by the numbers: Will Donald Trump hurt down-ballot Republicans?
As most polls show Hillary Clinton's lead over Donald Trump widening nationally, should other Republicans on the ballot worry about getting swept out with the tide in November?
After becoming the presumptive GOP nominee in May, Trump briefly pulled even in national polls with Clinton, the presumptive Democratic nominee. But he's since receded somewhat, and he now trails Clinton in every recent national survey. The margins vary - one survey puts Clinton two points ahead, another finds her up by 12 - but most polling averages show her with a comfortable six or seven point lead.
If she can maintain that edge, she'll score a convincing victory in November. And that could be bad news for down-ballot Republicans in House and Senate races who count on the head of their party's ticket to mount a strong campaign and help them cross the finish line.
The practice of ticket-splitting, in which a voter votes for one party at the presidential level and the other party in statewide or congressional races, has become exceedingly rare in recent years. In 2012, according to the Washington Post, only 5.7 percent of congressional districts voted for one party in the presidential race and the other party in the House race: a 90-year low. As recently as 1996, more than 25 percent of congressional districts split their vote in such a way.
What that means, effectively, is that parties sink or swim together in this age of increased partisan rigidity. If Trump tanks badly in November, he'll likely drag a lot of Republicans down with him, and the same is true of Clinton and down-ballot Democrats.
Generic numbers
The latest CBS News battleground tracker poll asked respondents in Wisconsin, North Carolina, Colorado, and Florida to pick a generic Democratic Senate candidate or a generic Republican Senate candidate. In all four states, the Democrat edged out the Republican.
In Colorado, the margin was the narrowest - 38 percent for the Democrat, 39 percent for the Republican, with 20 percent undecided. In Wisconsin, though, the Democrat was ahead 44 to 38, and in North Carolina, the Democrat was ahead 42 to 37.
In Florida, the generic Democrat was ahead 42 to 37 percent. That race may be a unique case, however, as Sen. Marco Rubio announced last week that he would seek reelection despite an earlier pledge not to run again. Given his visibility within the party, and the differences he expressed with Trump during his own presidential campaign, Rubio may be more able than most Republican candidates to distance himself from the GOP nominee. Still, as he begins his reelection campaign, his numbers aren't stellar: only 44 percent of likely Florida voters said they approve of the job he's doing as senator; 56 percent disapproved.
Adding to GOP worries, there's evidence to suggest Trump is damaging voters' perceptions of the Republican Party as a whole. In Florida, 19 percent of likely voters said Trump's campaign made them think better of the GOP, 49 percent said it made them think worse, and 32 percent said it had no effect. In Wisconsin, the numbers were even more damning: only 9 percent said Trump improved their outlook on the GOP, while 59 percent said it made their outlook worse.
Clinton simply hasn't dealt the same damage to her party's image: a plurality of voters in both Florida and Wisconsin said her campaign hadn't changed their impression of the Democratic Party.
Specific races
It's a long way to November, but thus far, some swing state Republicans seem to be holding their own. Pennsylvania GOP Sen. Pat Toomey is nine points ahead of his Democratic challenger, Katie McGinty, according to Quinnipiac numbers released last week. (An online survey from Public Policy Pollling, a Democratic outfit, found a tighter race, with Toomey ahead by just one point, 40 to 39 percent.)
In Ohio, Quinnipiac found GOP Sen. Rob Portman and Democratic challenger Ted Strickland, a former governor of the state, tied at 42 percent apiece.
In Florida, Quinnipiac found Rubio ahead of his likely Democratic challenger Rep. Patrick Murphy, by seven points. But a Bay News 9/Survey USA poll out this week found the race tied at 43 percent.
In Wisconsin, GOP Sen. Ron Johnson seems to be in trouble: former Sen. Russ Feingold, whom Johnson ousted in 2010, is campaigning to retake his old seat, and a Marquette University poll found him ahead of Johnson, 51 to 42 percent. Other recent polls have shown Johnson with a similar deficit.