Live Updates: Trump and Harris continue their campaign after the former president's visit to McDonald's

Vice President Kamala Harris and former President Donald Trump enter the final 15-day sprint to Election Day, engaged in an extremely tight race nationally and in the seven battleground states where they are spending the bulk of their time and resources as both candidates pursuing multiple paths to victory in November.

The Map: Harris and Trump are focusing on these seven crucial battlegrounds with events aimed at appealing to key groups of voters whose support could prove crucial in an election with razor-thin margins. The vice president will hold a series of events in three blue wall voting suburban districts on Monday, where she will join former GOP Rep. Liz Cheney in an effort to win over independent and Republican voters who continue to resist the former president, but may still have reservations about her candidacy.

Chester County, Pennsylvania, and Oakland County, Michigan, are two areas where Joe Biden extended the Democratic lead over Hillary Clinton's performance in 2016, while Waukesha County, Wisconsin, is a long-time Republican stronghold The Trump era has shown signs of erosion for Republicans.

Trump is scheduled to hold three events in North Carolina, the state that gave him the narrowest margin of victory four years ago. The state's 16 electoral votes are crucial to the former president's path to victory in November. If Harris is able to topple the Tar Heel State – which hasn't supported a Democrat at the presidential level since Barack Obama in 2008 – that would mean Trump has at least one of the Blue Wall states in addition to the others. States would have to withdraw from the Sun Belt contests to win the White House.

The money: When it comes to political campaigns, money isn't everything, but it's still important. According to the latest fundraising reports, Harris has a $346 million reserve for her political activities as of the beginning of October, far exceeding the nearly $285 million in funds available to her Republican rival. The vice president's main campaign committee more than tripled the amount Trump raised in September, capitalizing on that paid news advantage. David Wright and Fredreka Schouten report that the Harris campaign spent about $196 million on advertising in September, compared to Trump's $73 million, according to data from advertising tracking firm AdImpact.

The message: Harris and Trump spent the weekend escalating their attacks as both candidates' closing arguments took shape in the final days of the campaign.

For Harris, the strategy is to amplify Trump's rhetoric and use his comments from interviews and campaign appearances to portray her Republican rival as unfit for the presidency. The former president, meanwhile, is increasingly using inflammatory rhetoric and tactics aimed at discrediting his Democratic opponent as he completes his third presidential bid. On Sunday, Trump's campaign held an event at a McDonald's in Pennsylvania, where the former president briefly made french fries while claiming without evidence that Harris never worked at the fast-food restaurant, as she claimed. A campaign official told CNN that Harris worked at a McDonald's in California in the summer of 1983, while she was a student at Howard University.