The fight to repeal and replace Obamacare has begun.

The vote last week that was passed through the House was just the first stage, the bill will now need to make its way through the Senate, which is expected to be a much tougher journey.

With many senators already having concerns over the state of the bill, especially those who are facing re-election in the 2018 mid-terms, the minutiae will be looked at in great detail so as not to upset constituents.

One of the biggest issues surrounds the coverage of people with pre-existing conditions.

Looking at the states with the largest percentages of people under the age of 65 with pre-existing conditions, the GOP's plan goes south when it runs the risk of more adversely affecting those in states that voted for President Donald Trump.

The numbers that come from a 2016 study by the non-partisan Kaiser Family Foundation show that the 11 most affected states by coverage of people with pre-existing conditions, all voted for Trump.

States with highest levels of adults with pre-existing conditions:

West Virginia- 36%

Mississippi- 34%

Kentucky- 33%

Alabama- 33%

Arkansas- 32%

Tennessee- 32%

Oklahoma- 31%

Louisiana- 30%

Missouri- 30%

Indiana- 30%

Kansas- 30%

Republicans have electoral breathing space in most of these states and so may be able to withstand some degree of fallout even if the GOP plan doesn't work out as planned.

However, if the House GOP's change on pre-existing conditions means that people in the 11 states above can't get any sort of coverage, there could be a political price to pay.