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INDIANAPOLIS — Senator Ted Cruz of Texas, desperate to alter the course of a presidential primary fight in which Donald J. Trump is closing in on victory, will announce Wednesday afternoon that Carly Fiorina will be his running mate if he wins the Republican nomination, two campaign advisers confirmed.
The move, a day after Mr. Trump scored unexpectedly wide victory margins in sweeping five East Coast states, amounts to the grandest diversionary tactic a presidential candidate can stage — or at least the grandest one available to a candidate trailing by more than 400 delegates who failed to win more than 25 percent of the vote in any state on Tuesday.
Mr. Cruz’s decision to rush out a vice-presidential pick before next week’s primary in Indiana, which is becoming make-or-break for his candidacy, could serve to direct attention away from unflattering headlines about both Mr. Trump’s success and the wheezing alliance between Mr. Cruz and Gov. John Kasich of Ohio, who agreed to clear out of Indiana if Mr. Cruz withdrew from competition in Oregon and New Mexico.
And since endorsing Mr. Cruz last month, Mrs. Fiorina, the former presidential candidate and Hewlett-Packard chief executive, has proved to be an eager surrogate, attacking both Mr. Trump and Hillary Clinton with zeal.
Indeed, Mr. Cruz’s gambit may present a perilous challenge for Mr. Trump, who faces mounting criticism for his derisive remarks about women, including his repeated claims that Mrs. Clinton’s sole political asset is “the woman card.”
Already viewed unfavorably by a majority of women in general election polls, Mr. Trump has clashed savagely with Mrs. Fiorina in the past. He has mocked her business record, her voice and even her looks. “Look at that face,” Mr. Trump said in an interview with Rolling Stone magazine last summer. “Would anyone vote for that?”
Another slashing comment directed at Mrs. Fiorina’s appearance or gender could have grave consequences for Mr. Trump, especially with female voters he would need to win over to compete in the fall.