Here is the note for the Fox poll:
The Fox News poll is based on landline and cell phone interviews with approximately 1000 randomly chosen registered voters nationwide and is conducted under the joint direction of Beacon Research (D) (formerly known as Anderson Robbins Research) and Shaw & Company Research ®. For the total sample, it has a margin of sampling error of plus or minus 3 percentage points. When necessary, minor weights are applied to age, race, education and gender variables to bring the sample into conformity with the most reliable demographic profiles. Fox News polls are not weighted by political party. Results from Fox News polls before February 2011 were conducted by Opinion Dynamics Corp. Anderson Robbins Research changed its name to Beacon Research in 2019; the polling team is unchanged since 2011.
The Rasmussen poll matches the demographics for party and it is limited to likely voters. Those may be key factors given the tiny portion of people who answer the phone these days.