Answer:
Because James Polk was the president that signed the bill that accepted Texas as one of the States in the United States.
Step-by-step explanation:
Following the defeat of Henry Clay in the Presidential election in which James Polk won in 1844.
President James later in the following year signed the bill that accepted Texas as one of the states of United States.
The bill was signed on December 29, 1845, and Texas formally joined the union on February 19, 1846.
Hence, the election of President Polk was important to Texas "because James Polk was the president that signed the bill that accepted Texas as one of the States in the United States."