President Biden’s campaign said on Friday that it would spend $50 million on advertising in the month of July, a sign that his re-election effort is trying to power through a crisis threatening to end his candidacy by sticking largely to its usual playbook.

The ad buy matches what the campaign said it spent in June, a media blitz that did little to improve his lagging poll numbers. A New York Times/Siena College poll conducted after last week’s presidential debate found Mr. Trump holding his largest lead of the race.

The new ads will air online and on television and radio and will focus on Mr. Biden’s key issues: abortion, economic fairness and democracy. The campaign also said that Mr. Biden, Vice President Kamala Harris and their respective spouses would, between the four of them, travel to every battleground state this month. And it plans to invest $17 million in a door-knocking effort in July and August.

Taken together, the efforts represent a push by Mr. Biden’s campaign for stability and normality at an extraordinary time when some members of his own party have called for him to drop out. Alarmed by his fumbling debate performance last week, many Democrats are urging Mr. Biden to shake things up and prove he has the stamina and mental fortitude to beat former President Donald J. Trump, including by doing more interviews with mainstream journalists and speaking without the use of a teleprompter.

So far this week, Mr. Biden’s public appearances have been short and scripted. He sat for two interviews in friendly settings with Black talk radio hosts but stumbled his way through them. On Friday, he is likely to face much sharper questions, sitting for an interview with George Stephanopoulos of ABC News that will air in the evening. He will also deliver a campaign speech in Wisconsin on Friday and another in Pennsylvania on Sunday.

Campaign officials insist that the race remains close, despite Mr. Biden’s tough week. They describe a long election where repeated and early ad spending are needed to break through to voters. And both they and the president have publicly batted down any suggestion that he would drop out.

But they have seemed to acknowledge that some changes may be necessary.

In a news release announcing the $50 million July ad buy, the campaign said Mr. Biden would “engage in frequent off-the-cuff moments” this month. It pointed as an example to a post-debate trip the president made to a Waffle House in Atlanta that spawned a viral video after he “gave dap” to a patron.