Speaking at the virtual Conservative Party conference earlier, Ms Patel took aim at some of the tactics used during demonstrations over the summer and promised to give the police more resources to prevent similar scenes in future.
Protesters threw objects at police in Westminster and a statue of slave trader Edward Colston was toppled in Bristol during angry demonstrations in the wake of the death of George Floyd in America.
A statue of Sir Winston Churchill has been repeatedly vandalised and had to be boarded up to protect it during the Black Lives Matter protests.
Environmental activists also blockaded the printing presses of major newspaper groups last month, bringing widespread condemnation.
Ms Patel said there was ‘no excuse’ for the behaviour shown, adding the police had the ‘backing of the Government, the party, and the Prime Minister’ in their efforts to police the demonstrations.
She told Tory party members: ‘This Government will always defend the right to protest. That right is a fundamental pillar of our democracy, but the hooliganism and thuggery we have seen is not – it is indefensible.
‘There is no excuse for pelting flares at brave police officers, for throwing bikes at police horses, for disrespecting the Cenotaph or vandalising the statue of Sir Winston Churchill, one of the greatest protectors of our freedoms who has ever lived.
‘It is not acceptable for mobs to tear down statues and cause criminal damage across our streets. And it is not acceptable for thugs to assault our police officers, just for doing their job.’
She said the Government had already agreed to double the maximum sentence for assaults on emergency workers and confirmed she was working with chief constables to ensure their officers ‘have the tools, support and the powers they need’ to police such incidents.
Ms Patel also paid tribute to ‘hero’ Pc Andrew Harper, who died when he became trapped in a tow rope as he tried to stop quad bike thieves, and Sergeant Matt Ratana, who was shot as he prepared to search a suspect who was handcuffed.
She vowed to work with Pc Harper’s widow, Lissie Harper, to ‘ensure anyone who kills an emergency worker gets the sentence they deserve’.
In an announcement that had already been trailed in the media ahead of the speech, the home secretary committed to delivering ‘the biggest overhaul of our asylum system in decades’.
She said she would ‘explore all practical measures and options to deter illegal migration’.
It comes as ministers and officials faced a backlash last week over a string of reports on possible ideas for how to make changes to the asylum system, including processing those with claims on Ascension Island, some 4,000 miles from the UK, and placing them on disused ferries in the sea.
A fool isn’t someone who is wrong, a fool is someone who is afraid of being wrong.