"Preemption has gained a new valence during this time of heightened political polarization. Tensions between governors and mayors have escalated in past few years with the tendency of republican-leaning state legislatures to preempt and even punish democratic-leaning local governments for enacting policies such as designating themselves as a “sanctuary city” to shield their undocumented immigrant population from the harsh deportation practices of the federal government. Mayors pushing progressive agendas are increasingly running into a wall of conservative state resistance through what some view as aggressive, and even “nuclear”, state preemption. There are hints of resistance that runs the other way as well, with more conservative cities and counties enacting “second amendment sanctuary” resolutions in response to the adoption of stricter gun controls by more progressive state legislatures." How does partisanship, or party politics, cause tension in a federalist government system?

By supporting contradicting policies.

Explanation:

The federalist government system is run by dividing the countries into smaller states. The country with give the state government with the power to regulate their own territory while still following the advice/directions from the central government.

A problem arise when different political parties started to take control over the government.

These parties usually have their own ideologies. So, the way the view how to solve certain issues are also different.  This caused a lot of infighting within the government body to determine which legislations should be passed by the government. This is what causing the tension within the federalist government.

the first two-party system consisted of the federalist party, who supported the ratification of the constitution, and the democratic-republican party or the anti-administration party (anti-federalists), who opposed the powerful central government, among others, that the constitution established when it took effect in