Jeb Bush, Lindsay Graham breaking pledge of supporting party candidate: Donald Trump

Early this week, Bush and Graham said that they would not support Trump, who has now emerged as the presumptive Republican presidential nominee

Republican presumptive presidential nominee Donald Trump has accused former contenders Jeb Bush and Lindsay Graham of breaking their own "binding pledge" of supporting the party candidate by not backing him in the White House race.

Early this week, both Bush and Graham went public to say that they would not support Trump, who has now emerged as the presumptive Republican presidential nominee.

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"Remember this, Jeb Bush signed a binding pledge. Lindsey Graham signed a binding pledge, that they would support and endorse. Now they're breaking it. They are not honorable people when they do that because they're going against the pledge," Trump said.

Of the 17 Republicans, including Bush and Graham, in race for White House early this year, Trump is the only candidate left in the ongoing primary.

Talking about the taxation issue, Trump said he would simplify the taxes.

"It's quite simple to see. It's a simplification. We lower the number of brackets. We lower the taxes on the middle class, on business and we lower the taxes on everybody very substantially," he was quoted by saying by NBC.

During the interview, Trump said his tax plans are likely to change after negotiations in the Congress. The rival Clinton camp was quick to slam him.

"Don't believe Donald Trump's weak attempts at a general election 'makeover' for even a second," Clinton's deputy communications director Christina Reynolds said in a statement.

"Trump's economic plans take direct aim at working Americans - his proposal to cut trillions in taxes for the top 1% would almost certainly come at the expense of working and middle class families. Americans just can't afford Trump's economic plans," he said.

Meanwhile, Senator Bernie Sanders, a Democratic presidential candidate, yesterday said that he is the best candidate to defeat Trump.

"Donald Trump must not become president and I am happy to tell you that Donald Trump will not become president of the United States," Sanders told more than 6,750 supporters at the Rutgers Athletic Center.

Sanders pointed to national and state polls consistently showing that he defeats the likely Republican Party presidential nominee by margins nearly twice as great as Clinton's lead over Trump.

"If Democrats want to have the strongest candidate against Donald Trump they should look at those polls," Sanders said.