**MIMI WALTERS** District 45: Central Orange County: Irvine, Lake Forest R+03: Safeness of Seat 46%: Percent of Returns 8.5% Percent of AGI of AGI $2.97 billion SALT in 2014 340,000 tax returns in 2014 $34.883 billion AGI in 2014 $2.9682 billion deduction amount in 2014 26.8%: Income <$50K/year 8.3% : Poverty Rate 51.4%: White Collar 13.8%: Income >$200K/year
46% of tax returns in Mimi Walters's 45th California Congressional District in 2014 would have been penalized had state and local tax payments been added into the federal income tax base. The total increase in the tax base in 2014 would have been 2.97 billion dollars. We do not have sufficient detail to produce a precise estimate of how much taxes would have gone up—the Trump administration could, if it wanted to—but the rough ballpark number is 1 billion: the Republican tax bill will, if enacted, take 1 billion dollars a year out of the incomes and spending of Mimi Walters's constituents.
As a rich suburban district in Greater Los Angeles, the 45th contains a substantial slice of people who are possible beneficiaries from the tax bill: 13.8% of returns in 2014 reported adjusted gross incomes greater than 200,000 dollars a year. But by the same token that was less than one-third of the number of returns that itemized SALT.
The 45th is not a terribly safe Republican district. In 1988, the Almanac of American Politics reports, Orange County in which the 45th lies was the strongest Republican county in the nation: Ronald Reagan's and before him Richard Nixon's base. But Orange County has changed over the years, and, as noted above, the highly enterprising and prosperous traditionally-Republican California upper middle class's concerns are not the Republican Party's core concerns any more.
Walters may have decided that the seat is going to flip, and sooner rather than later, and so it is time for her to focus on pleasing Washington leadership and lobbyists rather than representing constituents, district, and California.
(Assuming, of course, there has not been a programming mistake in moving from zipcode-level IRS Statistics of Income to Congressional District level. Programming mistakes are easy to make.)