One possible result of Taft winning by a much narrower margin than Eisenhower is that the Democrats might maintain control of the Senate and the House as well. Among the Republicans who narrowly won Senate races in OTL who might have lost in this ATL are Barry Goldwater (who defeated Ernest McFarland in AZ by 51.3-48.7) and Charles E. Potter (who defeated Blair Moody in MI 50.6-49.0).
https://en.wikipedia.org/wiki/1952_United_States_Senate_elections
(And if Goldwater isn't elected to the Senate in 1952, will he ever be? True, he easily defeated McFarland again in 1958, so one can argue that he could have been elected to the Senate for the first time then, even though it was a Democratic year nationally. But Goldwater was unlikely to have done as well in 1958 without the advantage of incumbency. And as for AZ's other Senate seat, Carl Hayden looks unbeatable, at least in 1956.)
In the House, the Republicans only won a very narrow majority in OTL--221-213.
https://en.wikipedia.org/wiki/1952_United_States_House_of_Representatives_elections A few Republicans who would probably have lost without Ike's coattails: Frank Small, Jr., MD-05 (won 50.4-49.6); Clarence Clifton Young, NV-at-large (won 50.5-49.5); Edward J. Bonin, PA-11 (won 50.2-49.8); Louis E. Graham, PA-25 (won 50.4-49.6); and Joel Broyhill, VA-10 (won 50.2-49.8).