Harris' candidacy reshapes strategies for key House and Senate races

WASHINGTON — The rapid replacement of President Joe Biden with Vice President Kamala Harris as the de facto Democratic nominee is reshaping the dynamics for both parties in key races set to decide control of Congress.

For Republicans, the calculus changes dramatically. Their candidates have embraced former President Donald Trump and were banking on tying Democrats to an aging and unpopular Biden in order to win competitive House and Senate races. Now they’re eyeing a way to pivot to Harris, and GOP operatives are already testing new lines of attack on her.

For Democrats, candidates in battleground races are still planning to localize their races as much as possible. But lawmakers and party operatives are now hoping they canbenefit from the wave of enthusiasm provided by Harris' campaign in down-ballot races.

Republican strategists said their priority is to craft and drive a negative portrait of Harris in the minds of voters, using some of the same issues they attacked Biden on, such as immigration, crime and inflation.

“What is going to be critical important for Republicans as a whole is to quickly define Kamala Harris,” said one GOP strategist, who was granted anonymity to speak candidly, adding that the party is already evaluating new messages in the field. “We have a very short runway to take the four or five most unpopular positions she has and brand her as a supporter of those.”

Speaker Mike Johnson, R-La., tested some of those lines on Tuesday.

"Crises owned by Kamala Harris: the border crisis, the inflation crisis, the crime crisis, everything happening with the economy, our national security, weakness on the world stage. She is an equal partner in all of that," Johnson told reporters. "What has she done other