This post includes an interactive data visualization, which is best viewed on a computer or tablet. However, if you must use your phone, at least turn it landscape.

Observe

First, just observe the visualization.

The y-axis is the SNAP Coverage of the Poverty Population while the x-axis is the year.

Each dot represents a state in each year.

The color of the dot corresponds to the state government trifecta party each year.

Hover

Next, hover over any dot to bring up a tooltip showing several statistics on SNAP and poverty in that state. The tooltip will show:

1. The trifecta party
2. The SNAP Coverage of the Poverty Population
3. The estimated number of people living in poverty
4. People in poverty as a percent of total population
5. The average people receiving SNAP benefits over the year
6. The percentage of the state's population receiving SNAP benefits

Highlight

Start typing a state name into the "Highlight State Name" box to highlight a state in the visualization.

You can also click on the colors in the trifecta party color legend to highlight the states in one trifecta party in the visualization.

Filter

Filter by trifecta party to remove all states besides those in the selected trifecta party. This is different from the highlighter because it will recalculate the statistics in the box-whisker plot for only the selected states, while the highlighter will not recalculate these statistics.

I have found both interesting to use. The highlighter does a better job showing you one party in context of the others, while the filter provides you with better statistics. Use both and see which you like better!

Prepare the SNAP data

1. Download the SNAP data from the USDA. The zip file is called "FY 69 through FY 25," and it is in the National and/or State Level Monthly and/or Annual Data section.
2. Stitch together the files and clean up all the blank rows to make the data readable by your data program of choice (I used Tableau).
3. Keep the "Participation Persons" data field. You will not need the other fields for the visualization.
4. Average all months of data for each state and year combination to get the annual average Participation Persons on SNAP for these two dimensions.

Prepare the SAIPE poverty data

1. Download the SAIPE State and County Estimates. This link will get you to the 2024 page. When on the page, download the file called, "US and All States and Counties.xls."
2. Navigate the SAIPE datasets to get all years back to 2003. You can also use an API to save time.
3. Clean-up all files to remove blank rows and ensure headers are the same.
4. Calculate the field "Year" by extracting the two-digit year from the middle of the File Path field. Make sure it is in date format.
5. Create a calculated field called "Location Type." Set it to "U.S." if the "County FIPS Code" is "000" and the "State FIPS Code" is "00." Set it to "State" if the "County FIPS Code" = "000." All other FIPS codes should be assigned to "County."
6. Download the 2020 Census codes for State and State Equivalents reference file (scroll down to "State and State Equivalents" section)
7. Join this file to the output of Step 5 by setting "StateFP" equal to "State FIPS Code." We are doing this to bring in full state names rather than working with just two-letter postal codes.
8. Keep only "Location Type" = "State"
9. Remove extra numerical data fields that are not needed. The only fields I kept were, "Poverty Estimate, All Ages" and "Poverty Percent ."

Create the trifecta status data table

1. Create a spreadsheet with all 50 states in the rows and years in the columns
2. Go to Ballotpedia. Scroll down to the "Trifecta Status by State (1990-Present)" section. If the year has all "R" or all "D" it has a trifecta. Add this to the spreadsheet in the correct year/state cell. If it is mixed, add "Divided" to the correct year/state cell. Build out the entire data table manually this way. NOTE: I tried to use AI to do this for me and it continually returned many errors. The only way I found to guarantee it's correct is to do it manually.
3. Pivot the table to create a DB with three fields - Year, State, and Trifecta Status

Join Poverty and SNAP data

1. Join the SAIPE poverty DB with the SNAP DB on State Name. Important: before you do this, make sure there are no abbreviations in the SNAP DB. Fix these to the full state name in the raw data before you join. If you missed any, check the join to make sure that you have all 50 states.

Join Poverty/SNAP data with trifecta data

1. Join the combined poverty and SNAP database with the pivoted trifecta status data table on "State Name" and "Year."

Finalize database

1. Create a calculated field called "SNAP Coverage of Poverty Population" by dividing "SNAP Participation Persons" by "Poverty Estimate, All Ages"
2. Create a calculated field called "SNAP Percent of Population" and set equal to, "SNAP Participation Persons" / ("Poverty Estimate, All Ages" / "Poverty Percent")
3. Remove any other extraneous fields to keep the final database nice and tidy and then output the database

Create Tableau visualization

I'm assuming you know the basics of Tableau in these instructions

1. Connect Tableau desktop to the finished database
2. Drag "Year" onto the Column field and "SNAP Percent of the Poverty Population" onto the Row field. Make sure "Year" is discrete data type.
3. Drag "Trifecta Status" onto the color card
4. Drag "State Name" onto the detail card
5. Drag all the fields you would like to display on hover onto the tooltip card. Format the tooltip with text, etc. by clicking on the tooltip card.
6. Drag "Trifecta Status" onto the Filters tray
7. Enable highlighter for "Trifecta Party"
8. Add some flair! Add your logo, change color scheme... make it yours!