What impressed the freshman senator from Iowa was the way it all fell into place.

"Nothing happenstance, but programmed long before the election," said Sen. Charles E. Grassley (R-Iowa) of the way President Reagan led up to his fiscal message to Congress last night.

First had been the Inaugural Address with quick action on hiring. Then had come the press conference, the nationwide television address, OMB Director David Stockman's "little black book," and finally last night's speech.

"I thought he was moving too slow, but now as I see it all falling together, it's just right," said Grassley.

"Don't overlook the president's incredible staff," Grassley cautioned, "but don't forget it takes a Reagan to articulate it. Look at Carter. There probably was no more professional guy in public relations than Gerald Rafshoon, but still Carter couldn't get it across."

Which was the kind of partisan remark some 200 members and guests of the American Newspaper Women's Club might have expected at a prespeech reception for new senators, particularly since all but one of the honorees were Republicans.

Grassley, a member of the House until he defeated former senator John Culver last November, serves on both the budget and finance committees. He called Reagan's proposals to reduce federal spending "pretty stiff medicine" certain to be swallowed if everybody gets a dose. And he saw the tax cuts as a little less important than getting inflation under control. There would be bipartisan support, he predicted, along with a "rough time" from the Democrats on appropriated cuts.

In another part of the Senate Caucus Room, where ANWC president Pat Hamilton and reception chairman Fay Wells had provided a roast beef and cheese, the freshman senator from Illinois, Democrat Alan Dixon, was putting it another way.

"I think a great many Democrats will support the proposals on a selective basis. And while I'm not committed to Kemp-Roth, I want to encourage saving in this country, and we need tax cuts to do it."

What bothered Dixon, a member of the agriculture committee, was that milk supports seem destined for substantial cuts, though tobacco supports do not.

"There might be some health problems to take into consideration," said a pensive Dixon. "I think that everything needs a close look."

Washington State's freshman senator, Republican Slade Gorton, said early voter feedback on the contents of Stockman's little black book seemed to be "cautiously favorable as long as everybody shares."

Won't that be precisely what he and his colleagues will be doing if a congressional pay raise is scrapped, somebody asked.

Gorton shrugged indifferently.

"I was a legislator and an attorney general so long," he said, "That I've learned never to count on a pay raise until you get it."