Stuart Levine's Electoral Predictions Links

The Economist

270towin Election Simulator Daily Analysis

270towin.com
This contains links to a number of analytical sites such as those from PredictIt, Politico, Charles Cook, and Larry Sabato

Real Clear Politics Presidential Approval
This contains links to most polls

Real Clear Politics: Biden v. Trump
This contains links to most polls

Real Clear Politics: Betting Odds
This contains links to a number of prediction sites

FiveThirtyEight
This contains links to most presidential polls and has good poll data for other races