In a series of national surveys taken after the highly consequential June 27 debate, former President Donald Trump has emerged as the leader against President Joe Biden in 11 out of 12 polls, according to Real Clear Politics' poll tracker. However, these surveys are divided on the performance of potential Biden replacements against Trump.

Despite facing calls from prominent figures and major news outlets to resign his candidacy following his disastrous debate performance, Biden has firmly rejected these demands. Over the past two days, no additional lawmakers have joined the calls for his resignation, and some Democrats have even shown public support for the president. One notable reversal came from Rep. Jerry Nadler, D-N.Y., who initially called for Biden's resignation in private but has now expressed support for him.

Biden, in a letter to congressional Democrats on Monday, stated that it was time for the debate-related discussions to come to an end and urged everyone to focus on moving forward. However, the polls reveal different outcomes when it comes to potential replacement candidates against Trump in November.

Among the Democrats commonly mentioned as potential replacements, Vice President Kamala Harris appears to perform better than others, including California Gov. Gavin Newsom and Michigan Gov. Gretchen Whitmer, if the election were held today. However, it is important to note that Harris and Biden perform similarly in some surveys, with varying results on who fares better against Trump.

The polls also acknowledge the limitations of capturing voter sentiment, as they cannot account for the impact of months of campaigning by a candidate who lacks the national name recognition that Harris enjoys. This factor could potentially sway voter sentiment in unforeseen ways.

Furthermore, polls conducted prior to the debate consistently indicated that Trump held leads over Biden in the seven crucial swing states, with the exception of North Carolina. These swing states were all won by Biden in the 2020 election, further highlighting the significance of these findings.

In a tightly contested race, the independent run of Robert F. Kennedy Jr. has the potential to influence the outcome. A survey from May found that Kennedy, along with independent candidates Cornell West and Jill Stein, widened Trump's lead over Biden from two points to five. Kennedy garnered 6% of voter support, while 10% remained undecided. Another poll showed that Trump's lead increased by two points when accounting for the three independent candidates on the ballot. The Times/Siena/Inquirer survey also discovered that Kennedy drew votes from key Biden supporters.

Demographic shifts in support have also become evident in recent polls, indicating a decline in support for Biden and the Democratic Party among Black, Latino, and younger voters. The preference for Biden over Trump has decreased among voters under 45 and Gen Z/millennials, particularly when third-party candidates are included. Similarly, Biden is now tied with Trump among Hispanic voters in the battleground states and trails behind among 18- to 29-year-olds, two groups that had strongly supported Biden in the previous election.

Moreover, Biden's support in Democratic strongholds such as New York has declined. While Biden currently leads Trump by nine points in New York, a May survey from Siena College shows a significant decrease compared to his 23-point victory over Trump in 2020.

As Biden and Trump prepare for a historic rematch after their respective party nominations in March, polls reveal historically low voter enthusiasm with both candidates having favorability ratings below 45%. The NBC poll found that only 64% of voters expressed a "very interested" sentiment towards this year's election, marking a 20-year low.

Trump has based his campaign on highlighting his legal troubles, accusing prosecutors and judges involved in his criminal cases of being influenced by Biden to hurt his chances of winning the election. However, no evidence has been presented to support this claim. Meanwhile, Biden has portrayed Trump as a threat to democracy, emphasizing his role in the January 6 Capitol riots and criticizing his Supreme Court justice appointments, particularly those who voted to overturn Roe v. Wade.

The economy, immigration, abortion, and inflation consistently emerged as top issues among voters in various surveys. The Times/Siena/Inquirer survey found that a majority trusts Trump over Biden when it comes to handling the economy, crime, and the Israeli-Palestinian conflict. However, Biden was trusted more than Trump on the issue of abortion.

The upcoming election will undoubtedly be a critical moment for both candidates, with polls indicating a closely contested race and numerous factors that could potentially sway the outcome.