WASHINGTON — A wave of criticism from Republicans and Democrats alike rose Thursday after GOP presidential front-runner Donald Trump insulted the physical appearance of Carly Fiorina, his party’s only female White House contender.

It’s a new test for the candidacy of the brash-talking Trump, whose standing in opinion polls has surged despite a series of comments that might well have doomed a traditional politician.

Governor Bobby Jindal of Louisiana called Trump ‘‘a madman,’’ while former Florida governor Jeb Bush dismissed Trump’s latest comments as ‘‘small and inappropriate.’’ Both are GOP contenders as well. And Fiorina, the target of Trump’s latest insult, suggested she was ‘‘getting under his skin.’’

In some ways, Thursday was a day no different from others in an unpredictable 2016 presidential primary campaign, a messy contest in which Trump has emerged as a dominant and divisive figure. But the day also featured an escalation of criticism from Trump’s detractors in both parties, who seem be multiplying.

The chorus of anti-Trump Republicans, in addition to Bush and Jindal, now includes fellow contenders Senators Rand Paul of Kentucky and Lindsey Graham of South Carolina, former New York governor George Pataki, and retired neurosurgeon Ben Carson, who is running second to Trump in several early polls and challenged Trump’s Christian faith this week.

In a speech at the National Press Club in Washington, Jindal called Trump an ‘‘egomaniacal madman who has no principles,’’ describing him as a ‘‘carnival act.’’

‘‘The silly summer season is over,’’ Jindal said. ‘‘It’s time to get serious about saving our country. It’s time to send Donald Trump back to reality TV.’’

In an interview on ABC’s ‘‘The View,’’ Trump said, ‘‘I do have a very big heart,’’ and then he offered a message directly to women: ‘‘I want to say that I cherish women, and I will protect women, and I will take care of women, and I have great respect for women.’’

He said his wife and daughter have encouraged him to speak more about ‘‘women’s health issues, because they know how strongly and committed I am to it.’’

‘‘Jeb Bush and to a large extent Hillary [Rodham Clinton] are not committed like I’m committed,’’ he said.

Bush, who has emerged as a leading Trump critic in recent weeks, came to Fiorina’s defense Thursday. He tweeted that the ‘‘demeaning remarks are small and inappropriate for anyone, much less a presidential candidate. Carly & country deserve better. Enough.’’

Associated Press

Walker vows to ‘wreak havoc’ on federal unions

EUREKA, Ill. — Republican presidential contender Scott Walker promised to tackle union power at the federal level as he did as governor in Wisconsin, saying in a fiery speech Thursday that he wants to ‘‘wreak havoc’’ on Washington.

The governor chose Ronald Reagan’s alma mater of Eureka College for a speech aimed at invigorating his flagging campaign less than a week before the second GOP debate. Walker spoke on the same stage where Reagan, as a freshman in 1928, gave a speech during a student strike he had helped organize, and his remarks were infused with references to the late president. Walker spoke in front of a banner reading ‘‘Wreaking Havoc on Washington.’’

Walker talked about Reagan’s firing of striking air traffic controllers in 1981, before turning to his own record and recounting how he ‘‘didn’t back down’’ when curbing collective bargaining power of Wisconsin public workers and passing a ‘‘right to work’’ law.

Associated Press

Democrats to stick with 6 debates

WASHINGTON — Facing increasing resistance from candidates and party officials, Democratic National Committee chairwoman Debbie Wasserman Schultz firmly stood by the plan to hold exactly six presidential debates.

“We’re having six debates – period,’’ the Florida congresswoman said at a Christian Science Monitor breakfast in Washington, repeating that pledge several times over the course of an hour.

“We’re not changing the process. We’re having six debates,’’ she added. “We’re having six debates and the candidates will be uninvited from any subsequent debates if they accept an invitation to a debate outside the six DNC-sanctioned debates.’’

Her comments came after two DNC vice chairs, US Representative Tulsi Gabbard of Hawaii and former Minneapolis mayor R.T. Rybak, made their concerns public on Wednesday, calling it “a mistake’’ to limit the process to six debates with the threat of penalizing candidates who participate in nonsanctioned debates. Former Maryland governor Martin O’Malley and Senator Bernie Sanders of Vermont have been most aggressive in agitating for more debates and former Secretary of State Hillary Rodham Clinton has said she would be open to considering more.

Wasserman Schultz argued Thursday that six debates hits a sweet spot, enough for voters to see plenty of interaction among the Democratic candidates and not so many as to burden their campaigns.

“The purpose of it is so we can make sure that the Democratic Party’s debate process doesn’t get out of control,’’ she said, pointing to the 2008 Democratic primary, which included 26 debates, a number that “I don’t think . . . was helpful.’’

Bloomberg News