Trump’s Push to Cut Payroll Taxes Opens a Democratic Line of Attack

Mr. Trump did not help matters with his imprecise explanation of what, exactly, he wanted to do with the payroll tax, which he suggested on Saturday he wanted to “terminate.” Social Security is mostly funded by payroll taxes, and getting rid of them would be a drastic change to the federal government’s revenue streams.

Larry Kudlow, Mr. Trump’s top economic adviser, said on Sunday that the president was referring to forgiving the payroll taxes that are deferred, explaining, “He did not mean that he’s eliminating the Social Security tax.” But on Monday, Mr. Trump used similar language, saying that if he wins re-election, “we will be ending that tax; we’ll be terminating that tax.”

And his campaign advisers have been eager to highlight a sweeping action. “This is actually the biggest news of the day: President Trump said if he is re-elected, he will look into terminating the payroll tax permanently!” tweeted the campaign’s senior legal adviser, Jenna Ellis.

Whatever the president meant, just broaching the subject is giving Democrats additional ammunition in their effort to appeal to older Americans.

The Democratic Congressional Campaign Committee demanded to know if Republican lawmakers supported Mr. Trump’s effort to, as the committee put it, “deliver a devastating blow to seniors already reeling from this health and economic crisis.” And the Democratic National Committee is planning efforts in battleground states to draw attention to the matter.

The president’s move also allowed Mr. Biden to go on the offensive on a subject that has been a potential vulnerability for him. In the Democratic primary, Mr. Biden came under criticism over his record on Social Security during his lengthy career in public office, such as his support in the 1980s for a freeze on government spending, including Social Security.

After the president’s action on payroll taxes, the Trump campaign tried to flip the issue on Mr. Biden, reprising the criticism he faced in the primary. The campaign sent out an email calling Mr. Biden “the only candidate in the race who has tried to cut Social Security benefits.”