Republicans launch coordinated effort against Biden's 'heir apparent' Kamala Harris as she skirts question on whether she'll step in as Dem nominee

Republicans are taking aim at Vice President Kamala Harris as President Biden faces mounting calls to step aside as the Democratic presidential nominee paving the way for the vice president to potentially top the ticket come November. 

The vice president has been a staunch defender of the president and has pushed back on concerns over his poor debate performance and age. 

But some Democrats have already called for the president to drop out and Harris has been touted as a likely successor. 

Republicans are seizing on the fallout, accusing Democrats of covering up the president's true fitness and taking aim at Democrats in battleground states up and down the ballot.

The Republican House campaign arm on Wednesday launched a digital ad zeroing in on the vice president as Republicans look to hold the House and expand their slim majority this fall. 

The ad accuses Harris of being an 'enabler in chief' with clips of her praising Biden. 

It also accuses the vice president of being the 'architect of the border crisis' as a leading administration official tasked with addressing the border.

The digital spot ends 'Vote Republican. Stop Kamala.' 

'Whether extreme House Democrats call on Joe Biden to step aside or not, Kamala Harris deserves the blame for many of the crises making life unsafe and difficult for American families -- and we plan to make her a prominent feature of the 2024 campaign,' said National Republican Campaign Committee Will Reinert in a statement.

But Democrats slammed the line of attack and efforts to tie the vice president to the border.

'Republicans are fooling themselves if they think the American public will blame anyone besides Donald Trump and his feckless band of Republican extremists and phony moderates who killed a bipartisan border deal - all in an attempt to score cheap political points,' said Courtney Rice, spokesperson for the Democratic Congressional Campaign Committee, in response.

The GOP attack ad on Harris comes as a new CNN poll shows the vice president within two points of Donald Trump in a hypothetical head-to-head matchup. 

She does better in the polling than President Biden against the ex-president or other Democrats who have been floated as a replacement. 

Former Ohio Congressman Tim Ryan became the first prominent Democrat this week to call for Biden to step aside and for Democrats to make Harris the nominee.

Harris is the only potential replacement who would be able to seamlessly take control of the Biden campaign war chest should he drop out. 

But a Politico/Morning Consult poll last month found Harris has similar unfavorable ratings as Biden at 52 percent. 

For her part, Harris has rejected the prospect of being the party nominee so far. 

'Look, Joe Biden is our nominee. We beat Trump once and we're going to beat him again. Period,' Harris told CBS News on Tuesday. 

When asked if she is ready to lead the country if necessary, Harris responded 'I am proud to be Joe Biden's running mate.' 

The president and White House reiterated on Wednesday Biden would not be dropping out of the race.