The reason that economic arguments tend to trump (pardon the pun) environmental arguments when finding solutions to anthropogenic climate change, is because the senate is majority climate denying Republicans, who are more likely to respond to economic arguments. You could simply say, "renewable energy is better than fossil fuels, because renewable energy is better for the environment", but odds are Republican senators won't care until you also point out that the LCOE of renewable energy is less than the cost of fossil fuels. Republican senators will be needed to pass environments regulatory laws (now that Trump has destroyed the Clean Power Plan, new energy/ environmental regulations are needed), and hopefully a federal carbon pricing system. Also, since this is ostensibly a priority for ALL politicians, it should be highlighted that there are more jobs in renewable energy than fossil fuels.
Congressional republicans who continue to deny climate change don't necessarily have to want to protect the environment, or "give in" to the science behind anthropogenic climate change. Republicans can simply vote for energy policies that represent a cost savings; which tend to be renewable energy investments, over coal.
The cost of producing energy with renewable energy vs. fossil fuels is dramatically lower when just the cost of producing electricity (marginal cost) is considered. When the costs of the negative externalities associated with fossil fuel production are added in with the LCOE*, the relative cost of renewable energy sources vs. fossil fuels is lower still. Overall, the lowest cost of energy production is wind (which also has zero negative externalities), followed by natural gas (which carries the cost of negative externalities), followed by renewable energy sources, most significantly solar. Hydroelectricity also represents a relatively low cost source of domestic energy for the United States. Producing energy from coal is no longer cheaper than renewables or gas, and is very harmful to both the environment and public health.
"Levelized cost of electricity (LCOE) is often cited as a convenient summary measure of the overall competitiveness of different generating technologies. It represents the per-MWh cost (in discounted real dollars) of building and operating a generating plant over an assumed financial life and duty cycle. 4 Key inputs to calculating LCOE include capital costs, fuel costs, fixed and variable operations and maintenance (O&M) costs, financing costs, and an assumed utilization rate for each plant." - quote from the EIA
* Examples of levelized costs of energy include: up-front capital costs/ costs of initial investment (which are much higher for renewable energy than fossil fuel energy), marginal cost of the fuel source (which is much higher for fossil fuels, and almost nothing for free, abundant sources of renewable energy like solar and wind energy, and very low cost for hydro, geothermal, and biomass), cost of maintenance for the power plant/ energy farm/ dam, etc... , cost of transporting the fuel (again, zero for most renewable energy), costs associated with transmitting/ distributing the energy, insurance costs for the energy producing facility, etc... In this chart, you can clearly see how much more expensive nuclear and coal are projected to remain in comparison to renewables.
For the initial capital costs, nuclear is the most expensive form of energy. The "good" thing about nuclear energy production is that there are low marginal costs, and there are little to no negative externalities with regard to the actual energy production, i.e. little to no GHG emissions... and you just have to find Yucca mountains to bury the radioactive waste so people aren't exposed to potentially cancer-causing radiation... oh, and we have to hope that there's not a Fukushima-type catastrophe.
The major problems with new nuclear plants are: the potential for another Fukushima and/ or nuclear weapons proliferation, at least until 4th gen nuclear is ready to be produced and deployed, and the very high up-front capital cost of building new nuclear plants. The US Energy Information Administration estimated that for new nuclear plants in 2019 capital costs will make up 75% of the LCOE.
That said, 4th generation nuclear promises to be safe (if it ever gets built). New reactors can run on spent uranium and even thorium. 4th generation nuclear has entirely safe, cost efficient designs. Actually, the levelized cost of energy production from new, advanced nuclear reactors is looking viable, as you can see in this chart.