In a lengthy speech on the Senate Floor Thursday, Sen. Chuck Grassley (R-Iowa) picked apart House Democrats' recent move to attempt to obtain President Donald Trump's tax returns from his days as a private citizen.

"I have to say that if you take it at face value, it doesn't make a whole lot of sense," Grassley said of a letter sent by Rep. Richard Neal (D-Mass.), chairman of the Ways and Means Committee, to the Internal Revenue Service requesting the information.

Neal claimed in a statement that the request "is about policy, not politics," because his committee "has a duty to examine whether Congressional action may be needed" on how the IRS conducts audits of sitting presidents and vice presidents.

However, Grassley said that this reasoning doesn't quite add up.

"I, for one, haven't seen any evidence that the IRS has suddenly changed its policy under this president," Grassley said. "Why didn't they raise the issue under President [Barack] Obama, or President [George] Bush, or President [Bill] Clinton?

"The answer is nothing has changed," Grassley answered.

As chairman of the Finance Committee, Grassley has the same statutory power as Neal to request private tax returns for policy purposes, but he noted that there were other ways of evaluating IRS procedures without asking for Trump's pre-presidential tax information.

"If Democrats are truly interested in finding out the level of scrutiny given to a president's tax returns, why not simply just ask the IRS to describe its audit procedure?" Grassley said.

"Why is there a need to see President Trump's tax returns in order to get an answer to those questions?" he continued. "I'll give you a hint: There isn't one."

Grassley also countered Neal's claims that House lawmakers need the returns in order to evaluate whether or not the IRS is "enforcing the laws in a fair and impartial manner."

Given the fact that the request also asks for information on the status of any audits of Trump's businesses over the past six years, the senator said that "it sounds like they're planning to conduct their own review of the president's tax returns to see whether or not the IRS has been doing its job."

Rather, Grassley said, there isn't any evidence to believe that the IRS hasn't been doing its job when it comes to President Trump, and Democrats haven't offered any evidence to the contrary.

"And by the way," he continued, "if Democrats are really so concerned about enforcement, then why not ask the Treasury Inspector General to conduct a review of the IRS audit process?"

The reason, Grassley said, is because the request isn't really about conducting oversight of the IRS; it's about politics.

"What they are interested in is using their oversight authority to collect as much information about this president's finances as they can get their hands on," he said.

Noting the fact that Democrats have been calling for Trump's old tax information since the 2016 campaign, Grassley said the motives behind Neal's request are quite clear.

"It's motivated by Democrats' intense dislike for this president; It's motivated by their frustration over losing an election that they thought they'd easily win," he said "It's motivated by their desire to use all of the resources at their disposal to find something — anything — to bring this president down.

"You know, in all my years of conducting oversight, I have never started with an end result and then worked backward in search of a reason for making it happen," Grassley noted. "That's not how oversight is done."

"When you strip out all their pretexts, and when you strip out their circular logic, all you have are Democrats who want to go after the President any way they can," the senator concluded. "They dislike him with a passion, and they want his tax returns to destroy him. That's all this is about, and it's Nixonian to the core."