The phrase "back up an argument" is correct and usable in written English.
It is often used to describe the process of providing evidence to support an opinion or claim. For example, "I used research to back up my argument that increasing the minimum wage would have a positive economic impact."
The poll also found that 57 percent of voters think that continuing the race will be good for the party, backing up an argument Mr. Santorum has been putting forth; 33 percent say it would be better for him to drop out.
One of the great lessons of this exercise is to underline the dubiousness of using only statistics to back up any argument about who is the greatest racing driver of all time.
The secret of the bidders' willingness to take their chances as they operated anonymously over the telephone probably lies in the "Illyrian" qualifier — Ancient Illyria straddled several republics from the former Yugoslavia, limiting the risk of any one of these countries being able to back up a claim to restitution with compelling arguments.
In his statement, Trump cited a highly dubious poll from an organization known for peddling conspiracy theories to back up his argument that a large portion of American Muslims held jihadi or extremist views.
To back up the argument, we performed a rescue experiment of the DopR1 mutant LTM by expressing the wild-type transgene in the Kenyon cells.
To back up this argument, I thought I'd compile a list of some bullet points/suggestions one might want to cover if or when Banksy was included in a discussion or a class.
Tobin even included a quote from the pontiff to back up his argument.
President Donald Trump on Saturday again recited the lyrics to a song called "The Snake" to back up his argument against keeping certain people out of the United States. .
An oft-cited example to back up the argument for flexibility is that of the company which elects not to include the results of a money-losing subsidiary in its reported earnings.
