President Donald Trump is facing his first and biggest challenge to his "I Can Do Everything President" with his pledge to erase the Affordable Care Act, also known as Obamacare, to repeal and replace it with “something terrific”.

Speaking to a crowd of over 18,000 in Louisville, Kentucky, on Monday, Trump tried to make his pitch for popular support in a deep red state widely touted as one of the success stories of Obama’s Affordable Care Act (ACA), as reported in The Guardian.  

Kentucky is home of Senator Rand Paul, one of the most vocal critics of the health bill which is heading for a vote in the House on Thursday. While Trump was at the rally, Paul had already returned to Washington to meet with fellow conservative opponents of the bill, including Ted Cruz of Texas and Mike Lee of Utah, as well as members of the hard-right Freedom Caucus. 

Indeed, on Tuesday Trump turned up the pressure on wavering House Republicans to support his bill to overhaul the health care system, threatening G.O.P lawmakers with political retaliation and danger of losing their jobs if they don't support it.

“Many of you came in on the pledge to repeal and replace Obamacare. I honestly think many of you will lose your seats in 2018 if you don't get this done,” the president told lawmakers inside a private party meeting, according to a Republican in the room.

The countdown quickened toward the expected vote on Thursday on legislation undoing much of the law that has provided coverage to some 20 million Americans, including thousands of people who voted for Trump.

In the Republican stronghold of Bakersfield, Kern's County, California, 95,000 people depend on Obamacare, as reported in El País. Around 10% of Kern’s population will lose health cover after funding for Medicaid – the public health system extended by Obama – is cut, according to a study by the University of California, which says that more than 16,000 people will lose subsidies toward their private health insurance. Under Obamacare, the number of people without medical cover fell in the county from 18.2% to 7.9%. The study also estimates that withdrawing the funding will mean the loss of 5,000 jobs in the county. 

Kern is also the district of Kevin McCarthy, the Republican Majority Leader in the House of Representatives. McCarthy has made overturning Obamacare his personal crusade. Trump is trying to get his healthcare counter reform that would end Obama’s state aid enacted as quickly as possible.

Pressure is growing on Trump to deliver as investors become worried that a failed healthcare push could also portend trouble for promised tax cuts and relaxed regulation that have propelled the market to record highs in recent months.