Under which circumstances might a US president send federal soldiers to enforce order in estate would it be if the state needed help in collecting income tax, or if the states elected governor committed a crime, or if the state collected tolls on an interstate highway or the states police force could not keep the peace

Under the circumstances where a state cannot maintain law and order within its own jurisdiction, a US president might send federal soldiers to enforce order. Some potential scenarios could include:

1. Domestic insurrection: If there is an uprising or rebellion within a state that threatens public safety or the functioning of government, the president may use federal troops to restore order and protect citizens.

2. Obstruction of justice: If a state elected official, such as a governor, commits a crime that affects the functioning of state government or undermines the rule of law, the president might intervene to ensure justice is served.

3. National emergency: In case of a natural disaster or a national emergency, where a state's resources are overwhelmed, the president can deploy federal troops to assist in disaster response, rescue operations, or maintaining order.

4. Civil rights violations: If a state government or its law enforcement agencies violate the civil rights of its citizens or engage in discriminatory practices, the president may intervene to protect citizens' constitutional rights.

5. Aid in tax collection: While it is not common, there have been instances in the past where federal troops have been used to aid in tax collection efforts, particularly during times of significant unrest or resistance.

6. Interstate conflict: If states engage in conflicts over border disputes or other interstate issues, the president may deploy federal troops to prevent violence and maintain peace.

It is important to note that the use of federal soldiers to enforce order within a state is a rare and extreme measure, primarily employed under extraordinary circumstances that threaten public safety or disrupt the functioning of government.