For months, the campaign website for Adam Laxalt, the Republican Senate nominee in Nevada, greeted visitors with a huge banner exalting his endorsement from former President Donald J. Trump in all capital letters. Now, that information is nowhere on his home page.
Representative Ted Budd, the Republican Senate nominee in North Carolina, also made Mr. Trump’s endorsement far less prominent on his website last month. And Blake Masters, the party’s Senate nominee in Arizona, took down a false claim that the 2020 election had been stolen from Mr. Trump and softened his calls for tough abortion restrictions.
Republican leaders are increasingly worried that both Mr. Trump and the issue of abortion could be liabilities in November, threatening the advantages the party expected from President Biden’s unpopularity and voters’ distress over inflation. At least 10 Republican candidates in competitive races have updated their websites to downplay their ties to Mr. Trump or to adjust uncompromising stances on abortion. Some have removed material from their websites altogether.
The changes to the websites for Mr. Laxalt and Mr. Budd have not been previously reported. Mr. Masters’s overhaul, in which he deleted, among other elements, a call for an anti-abortion constitutional amendment that would give fetuses the same rights as infants and adults, was first reported by NBC News and CNN. Other news outlets have identified editing by several House candidates, including Yesli Vega in Virginia and Barbara Kirkmeyer in Colorado, Bo Hines in North Carolina and Tom Barrett in Michigan.
Candidates have long adjusted their messaging after winning primaries, appealing to general-election voters by toning down the hard-line stances they took to win over their party’s base. But now, such shifts are more visible.
“Having all this stuff in writing makes it a little more challenging to make the pivot,” said Whit Ayres, a longtime Republican pollster who is working with a super PAC supporting Senator Marco Rubio of Florida, among other groups. But, he added, “there are a couple of unusual elements that do make this a bit different, with the Dobbs decision and Trump’s continual prominence in the news.”
Anna Greenberg, a Democratic pollster who is working with several campaigns, including Mr. Masters’s opponent, Senator Mark Kelly, said that “the magnitude of the changes and the volume” among Republicans were well beyond what she had seen in past election cycles.
Mr. Laxalt, who is running against Senator Catherine Cortez Masto in a race that Republicans see as one of their best chances to pick up a Senate seat, updated his website sometime between July 10 and Aug. 3, according to archived versions reviewed by The New York Times — putting the changes at least a month beyond his June 14 primary win.
Brian Freimuth, a spokesman for Mr. Laxalt, called inquiries about the website changes — which moved mention of Mr. Trump’s backing to an “endorsements” page — “ridiculous” and said, “We are proud of our Trump endorsement.”
He added that the banner images on Mr. Laxalt’s Twitter and Facebook pages had “remained the same, emphasizing Trump’s endorsement.” Those banners, composite images of Mr. Laxalt, Mr. Trump and 12 other Republicans, feature Mr. Trump prominently but do not mention the endorsement.
Mr. Budd updated his website in late July, well after North Carolina’s May 17 primary, according to archived pages reviewed by The Times.
Until July 22, his home page featured a prominent, all-caps message that read “endorsed by President Donald J. Trump,” above a photo of Mr. Budd with the former president and a sign-up form urging voters to “join President Trump in supporting” him.
But since July 23, it has instead featured a rotating slide show of endorsers, starting with Lt. Gov. Mark Robinson of North Carolina and circulating through former Gov. Nikki Haley of South Carolina and Senator Marsha Blackburn of Tennessee before reaching Mr. Trump. A viewer would need to look at that spot on the page for about 20 seconds to see Mr. Trump.
“It’s pretty basic — general elections have different dynamics than primary elections,” Jonathan Felts, a spokesman for Mr. Budd’s campaign, said in an email.
“We face a female opponent, so we’ve added prominent female politicians who have endorsed Ted,” Mr. Felts said. (Mr. Budd’s Democratic opponent is Cheri Beasley, a former chief justice of the North Carolina Supreme Court.)
Other differences have been more subtle. Mr. Budd, for example, has made no changes to a page that outlines his views on abortion, but he has moved the link to that page lower on his website’s list of his positions; it was second as of July 23, but is now fifth.
J.D. Vance, the Republican Senate nominee in Ohio, once listed abortion sixth on his “issues” page, but now lists it 10th.
Sometime between Aug. 7 and Aug. 26, Mr. Vance also expanded his abortion language on that page to emphasize government support — including an expanded child tax credit — to ensure “that every young mother has the resources to bring new life into the world.” He has made no changes, however, to his description of himself as “100 percent pro-life.”
Recent polls and elections underscore the dangers of the current political environment for Republicans. Since the Supreme Court overturned Roe v. Wade in June and abortion bans took effect in many states, Democrats have exceeded expectations in four special House elections, and Kansans decisively rejected a constitutional amendment that would have paved the way for an abortion ban or major restrictions.
And now, the widening F.B.I. investigation of Mr. Trump’s handling of classified documents is shining a light on the former president when Republicans would rather have voters focus on the current one.
A Quinnipiac University poll released Wednesday found that Mr. Biden’s approval rating, while still low at 40 percent, had increased nine percentage points since July and exceeded Mr. Trump’s 34 percent rating, with a margin of error of plus or minus 2.5 percentage points.
The poll also found that 76 percent of respondents were following the news about the removal of classified documents from Mr. Trump’s home somewhat or very closely and that 64 percent considered the allegations against him somewhat or very serious.
Eighty-three percent of Americans polled said it was important that candidates share their views on abortion, and 64 percent said abortion should be legal in all or most cases. Republicans are not alone in recognizing the salience of the issue; Democrats have also taken note, adjusting their own messaging and spending millions of dollars on abortion-related advertising.
“It could be the case that in a tight race, the abortion issue could tip the balance,” said Mary C. Snow, a Quinnipiac polling analyst.