If the new Republican plan to replace the Affordable Care Act passes as written, many older Americans will be paying more money for less coverage, and getting less government help to do so.

Under the new plan, the tax credits that help subsidize individual plans will be based largely on age, and no longer will take income or location into account. They will also cap at $4,000, as opposed to ACA credits, which can go as high as $15,000. As result, people who got an extra boost in tax credits to help pay for their health insurance because they earn a low income will not longer get that help.

This will be particularly bad for the age 50-64 age group, which "likely total more than 63 million today— [and] tend to be fairly robust consumers of health care services, but are too young to be covered by Medicare," according to an article in Fortune magazine.

Senator Bob Casey (D-Penn.) used Twitter to lay out exactly how his constituents in this demographic will suffer under the new plan.

Senator Casey used information from an interactive map by the healthcare policy think tank the Kaiser Family Foundation to go county by county and show what Pennsylvanians older than 50 who don't qualify for Medicare will lose in tax credits and how much more they'll be paying for their health insurance.

According to Casey's tweets, members of that age group in 37 out of Pennsylvania's 67 counties will lose at least $5,000 in tax credits, with many losing more than $10,000 because their income will no longer be taken into account. Their insurance costs will rise by as much as 75 percent in some counties.

And while the state narrowly went to Donald Trump in the 2016 election, the pain of what Casey's tweets refer to as the "age tax" is spread around the entire state, not taking political preference or income level into account.

Lancaster County was the largest in the state to vote for Trump, and 50-64 year-olds there will lose $11,020 in credits, among the highest cuts in subsidies.

Similarly large, red counties like York and Berks will take similar hits of $11,020, while the three largest in the state, all which voted for Hillary Clinton, will lose credits as well. The cuts don't discriminate by income, as some of the lowest income counties in the state take the hardest hits, while the wealthy suburbs of Philadelphia don't.

According to the Kaiser Family Foundation map, such scenes are going to be repeated around the country, as seniors in only a few states will consistently see low decreases or increases in tax credits.

For almost everyone else, costs will rise. Senator Casey, at least, wants his constituents to be prepared for what might be ahead.