The Cook Political Report on Thursday shifted Arizona from “toss up” to “lean Democrat,” as multiple polls show Democratic nominee Joe Biden with a lead against incumbent Republican President Donald Trump. 

A Monmouth University survey released Thursday showed Biden leading Trump among registered voters by 4 points in Arizona, 48% to 44%. A Kaiser Family Foundation poll published the same day showed Biden with a 5-point edge in the state, 45% to 40%. 

Arizona is a vital battleground state in the November election, with 11 electoral votes. Trump won Arizona in 2016 against Democratic candidate Hillary Clinton, 48.1% to 44.6%.

“Arizona is geographically large, but its population is concentrated in Maricopa County (Phoenix). About two-thirds of the vote comes from Maricopa. Voters there, as in other suburban areas in and around big metro areas, have soured on Pres. Trump,” Amy Walter, national editor for the Cook Report, said in a blog post. In 2016, Trump held off Clinton in Maricopa County, 47.7% to 44.8%. 

“Another troubling sign for Trump in Arizona is that GOP voters are not as committed to supporting him as they are in the other Sun Belt states. Call it the revenge of former Arizona GOP Sens. Jeff Flake and the late John McCain, two of the president's most vocal critics,” she continued. Trump has famously derided McCain, claiming he is not a war hero because he was captured during the Vietnam War. 

On Monday, Trump visited Arizona for a “Latinos for Trump” event. Biden has yet to campaign in Arizona but is expected to reach the state in the coming weeks.

An important Senate race is also taking place in Arizona. The Monmouth poll shows Democrat Mark Kelly leading Republican Sen. Martha McSally by 4 points in the state, 50% to 46%.

Recent general election polls show Biden with a strong nationwide lead over Trump. A Reuters/Ipsos survey released Wednesday shows Biden with a 9-point edge over the incumbent, 50% to 41%.