Subsidies that create inequities that are fixed with more subsidies is bad government.
To briefly summarize what Bruce Krasting is referring to, Exim is the Export-Import bank. Some of Exim’s loans have gone to foreign airlines so they can buy American-made airplanes. Which is fine, except because of that help those foreign airlines have a competitive advantage over American firms in the international airfare market. So Delta sued Exim over its aid to foreign airlines, and at least one member of congress thinks the answer is to give Delta (U.S.) subsidies to offset the disadvantages it has because of (U.S.) subsidies for its foreign competitors.
And I completely agree with Krasting, that is a very bad idea. Fix the problem and get out of the market; do not keep adding on more “solutions” (which involve sending taxpayer money to someone) which in turn cause more problems that require more “solutions” (which involve sending taxpayer money to someone).