As of mid-February, FiveThirtyEight had Trump’s approval rating at 41.6 percent while 54 percent disapproved of his job performance. A CNN analysis of approval ratings correlated with party identification estimates that just 20 percent of the U.S. population over the age of 18 is Republicans who approve of Trump. A Brookings Report has noted erosion in both mainstream political parties as more voters declare themselves independents. However, the erosion has been strongest within the Republican Party since Trump’s election in 2016. To win in 2020, Trump needs to expand his base but appears unwilling or incapable of doing so.