US Elections: One week after National Convention poll shows Clinton support on the rise

One week after the end of their national convention, a more unified Democratic party sees a new surge of confidence in Hillary Clinton’s chances of winning the presidential election in November.

Amid a number of polemics by their nominee, Donald Trump, the Republicans have seen the leverage they obtained from their party’s convention wither away. That disparity is reflected in a spate of polls this past week, including a new Wall Street Journal/NBC News poll released Saturday that found Mrs. Clinton and her party in a stronger position on a number of fronts.

She now is drawing more support from backers of her primary rival, Sen. Bernie Sanders. More voters would prefer that Democrats win control of Congress than prefer Republican control, by a slight margin. And among Democrats, there is a post-election surge of optimism that the nation is on the right track.

“Their convention was a success at making their party feel good about the direction of the country,” said Bill McInturff, a Republican pollster who conducted the survey with Democratic pollster Fred Yang. “The Republican convention was unable to budge the number of Republicans voting for Donald Trump.”

The Democratic mood swing was clear when voters were asked whether they thought the country was on the right track or moving in the wrong direction. Democrats saw the sunny side by a 58%-35% margin. Just a month ago, the mood was the opposite, with only 33% saying right track and 56% saying wrong direction. Republicans remained pessimistic after the conventions, with 91% saying the country was moving in the wrong direction.

Asked which party they want to control Congress, 47% said Democrats, 43% said Republican—a shift from last month, when the parties tied on that question. If that trend continues, it could signal that Mr. Trump is becoming a drag on Republicans elsewhere on the ballot such as House and Senate candidates.

It remains to be seen how durable the gains made by Mrs. Clinton and her party will be, in a campaign that has been unpredictable from the outset. This cycle already has seen Mr. Trump survive and even thrive after controversies that would destroy other politicians.

The Journal/NBC News poll of 800 registered voters was conducted July 31 through Aug. 3, after both parties’ national conventions and after Mr. Trump became mired in controversy for criticising Khizr Khan, the father of an American Muslim soldier killed in Iraq.

The poll found Mrs. Clinton leading Mr. Trump 47%-38%, widening her lead more because of erosion of support for Mr. Trump rather than growing support for her. Last month’s poll put Mrs. Clinton ahead 46%-41%.

One improvement likely to endure is the support Mrs. Clinton picked up among Sanders supporters, which rose to 86% in the new poll.

That is up from July, when 76% of Sanders voters said they would back her against Mr. Trump. However, despite the positive outlook, in the same survey Mrs. Clinton continues to struggle with her trustworthiness: Just 22% say she is honest and straightforward, compared with 35% who say that about Mr. Trump.