Paul retired from the Marine Corps on May 31, 2013 and returned to his home town of Waterloo, Illinois. He accepted an "Of Counsel" position with the law firm of Stumpf & Gutknecht, P.C. in Columbia, Illinois.
In 2014, Paul was the Republican candidate for Illinois Attorney General. Although he lost the election to 12 year incumbent Lisa Madigan, he carried 68 out of 102 Illinois counties.
In 2016, Paul, despite being outspent by over $300,000, was elected to the Illinois State Senate by over 20 points when running against the former Lieutenant Governor of Illinois. During his time in the legislature, Paul served on the Illinois Senate's Judiciary, Telecommunications, Agriculture, Commerce & Economic Development, Financial Institutions, Energy & Public Utilities, and Transportation committees. Paul was the minority spokesman for the Illinois Senate's Veterans' Affairs Committee.